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  #1   Report Post  
Colin B.
 
Posts: n/a
Default Tuner repair pointers

Hey all;

Next on my agenda is to fix up an old but fantastic tuner I have here;
a Pioneer TX-9800.

Now I'm not looking at doing a full alignment--that can be left for the
professionals. However the major problem seems like it should be easily
fixable. Basically, the tuning jumps around terribly. If I'm tuned to
my favorite station (93.7, CKUA!), it'll be fine for a while and then
disappear entirely. To retune it, I have to go to 94.1; and the tuning
capacitor sounds (and looks on the meters) NOISY when I turn it.

Any pointers? Once I get it out of my rack, I'm going to look for crap
on the tuning cap, but beyond that, I'm not sure.

Thanks!
Colin
  #2   Report Post  
Mark D. Zacharias
 
Posts: n/a
Default Tuner repair pointers

Blow out the tuning capacitor with a compressor. Fairly common problem.
Naturally happens more towards the lower end of the scale, since this is
where the tuning capacitor's vanes are fully meshing.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Colin B." wrote in message
...
Hey all;

Next on my agenda is to fix up an old but fantastic tuner I have here;
a Pioneer TX-9800.

Now I'm not looking at doing a full alignment--that can be left for the
professionals. However the major problem seems like it should be easily
fixable. Basically, the tuning jumps around terribly. If I'm tuned to
my favorite station (93.7, CKUA!), it'll be fine for a while and then
disappear entirely. To retune it, I have to go to 94.1; and the tuning
capacitor sounds (and looks on the meters) NOISY when I turn it.

Any pointers? Once I get it out of my rack, I'm going to look for crap
on the tuning cap, but beyond that, I'm not sure.

Thanks!
Colin



  #3   Report Post  
Mark D. Zacharias
 
Posts: n/a
Default Tuner repair pointers

Blow out the tuning capacitor with a compressor. Fairly common problem.
Naturally happens more towards the lower end of the scale, since this is
where the tuning capacitor's vanes are fully meshing.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Colin B." wrote in message
...
Hey all;

Next on my agenda is to fix up an old but fantastic tuner I have here;
a Pioneer TX-9800.

Now I'm not looking at doing a full alignment--that can be left for the
professionals. However the major problem seems like it should be easily
fixable. Basically, the tuning jumps around terribly. If I'm tuned to
my favorite station (93.7, CKUA!), it'll be fine for a while and then
disappear entirely. To retune it, I have to go to 94.1; and the tuning
capacitor sounds (and looks on the meters) NOISY when I turn it.

Any pointers? Once I get it out of my rack, I'm going to look for crap
on the tuning cap, but beyond that, I'm not sure.

Thanks!
Colin



  #4   Report Post  
Mark D. Zacharias
 
Posts: n/a
Default Tuner repair pointers

Blow out the tuning capacitor with a compressor. Fairly common problem.
Naturally happens more towards the lower end of the scale, since this is
where the tuning capacitor's vanes are fully meshing.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Colin B." wrote in message
...
Hey all;

Next on my agenda is to fix up an old but fantastic tuner I have here;
a Pioneer TX-9800.

Now I'm not looking at doing a full alignment--that can be left for the
professionals. However the major problem seems like it should be easily
fixable. Basically, the tuning jumps around terribly. If I'm tuned to
my favorite station (93.7, CKUA!), it'll be fine for a while and then
disappear entirely. To retune it, I have to go to 94.1; and the tuning
capacitor sounds (and looks on the meters) NOISY when I turn it.

Any pointers? Once I get it out of my rack, I'm going to look for crap
on the tuning cap, but beyond that, I'm not sure.

Thanks!
Colin



  #5   Report Post  
Mark D. Zacharias
 
Posts: n/a
Default Tuner repair pointers

Blow out the tuning capacitor with a compressor. Fairly common problem.
Naturally happens more towards the lower end of the scale, since this is
where the tuning capacitor's vanes are fully meshing.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Colin B." wrote in message
...
Hey all;

Next on my agenda is to fix up an old but fantastic tuner I have here;
a Pioneer TX-9800.

Now I'm not looking at doing a full alignment--that can be left for the
professionals. However the major problem seems like it should be easily
fixable. Basically, the tuning jumps around terribly. If I'm tuned to
my favorite station (93.7, CKUA!), it'll be fine for a while and then
disappear entirely. To retune it, I have to go to 94.1; and the tuning
capacitor sounds (and looks on the meters) NOISY when I turn it.

Any pointers? Once I get it out of my rack, I'm going to look for crap
on the tuning cap, but beyond that, I'm not sure.

Thanks!
Colin





  #6   Report Post  
Barry Mann
 
Posts: n/a
Default Tuner repair pointers

In , on 04/21/04
at 05:14 PM, "Colin B." said:

[ ... ]

If I'm tuned to
my favorite station (93.7, CKUA!), it'll be fine for a while and then
disappear entirely. To retune it, I have to go to 94.1; and the tuning
capacitor sounds (and looks on the meters) NOISY when I turn it.


[ ... ]

In another reply, Mark has the right answer. If you look closely at the
tuning capacitor (the thing attached to the dial cord that looks like
an egg slicer) you'll see some very fine metal "whiskers" are shorting
the plates together. This is a standard mid-life crisis for analog
tuners.

When you blow out the whiskers, take care not to bend anything in the
general area and don't turn any of the screws.

I'll also use a tiny drop of contact cleaner at each of the bearings.
(This is not an attempt to lubricate or clean the bearings. The
japanese use a little clip beside each bearing to make good contact
with the moving vane. I'm just making sure that the contact is clean
and solid.)

Sometimes the trimmer capacitors (the screws on the main tuning
capacitor) will degrade and become intermittent. I've never been able
to develop a log term solution for that one. Sometimes, I can
temporarily improve the situation by injecting cleaner and rotating
them, but the problem usually returns. (You should not do this, unless
you are prepared to tweak the alignment) The whiskers will return in a
few years, but you can blow them out again.

-----------------------------------------------------------
spam:
wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13 (Barry Mann)
[sorry about the puzzle, spammers are ruining my mailbox]
-----------------------------------------------------------

  #7   Report Post  
Barry Mann
 
Posts: n/a
Default Tuner repair pointers

In , on 04/21/04
at 05:14 PM, "Colin B." said:

[ ... ]

If I'm tuned to
my favorite station (93.7, CKUA!), it'll be fine for a while and then
disappear entirely. To retune it, I have to go to 94.1; and the tuning
capacitor sounds (and looks on the meters) NOISY when I turn it.


[ ... ]

In another reply, Mark has the right answer. If you look closely at the
tuning capacitor (the thing attached to the dial cord that looks like
an egg slicer) you'll see some very fine metal "whiskers" are shorting
the plates together. This is a standard mid-life crisis for analog
tuners.

When you blow out the whiskers, take care not to bend anything in the
general area and don't turn any of the screws.

I'll also use a tiny drop of contact cleaner at each of the bearings.
(This is not an attempt to lubricate or clean the bearings. The
japanese use a little clip beside each bearing to make good contact
with the moving vane. I'm just making sure that the contact is clean
and solid.)

Sometimes the trimmer capacitors (the screws on the main tuning
capacitor) will degrade and become intermittent. I've never been able
to develop a log term solution for that one. Sometimes, I can
temporarily improve the situation by injecting cleaner and rotating
them, but the problem usually returns. (You should not do this, unless
you are prepared to tweak the alignment) The whiskers will return in a
few years, but you can blow them out again.

-----------------------------------------------------------
spam:
wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13 (Barry Mann)
[sorry about the puzzle, spammers are ruining my mailbox]
-----------------------------------------------------------

  #8   Report Post  
Barry Mann
 
Posts: n/a
Default Tuner repair pointers

In , on 04/21/04
at 05:14 PM, "Colin B." said:

[ ... ]

If I'm tuned to
my favorite station (93.7, CKUA!), it'll be fine for a while and then
disappear entirely. To retune it, I have to go to 94.1; and the tuning
capacitor sounds (and looks on the meters) NOISY when I turn it.


[ ... ]

In another reply, Mark has the right answer. If you look closely at the
tuning capacitor (the thing attached to the dial cord that looks like
an egg slicer) you'll see some very fine metal "whiskers" are shorting
the plates together. This is a standard mid-life crisis for analog
tuners.

When you blow out the whiskers, take care not to bend anything in the
general area and don't turn any of the screws.

I'll also use a tiny drop of contact cleaner at each of the bearings.
(This is not an attempt to lubricate or clean the bearings. The
japanese use a little clip beside each bearing to make good contact
with the moving vane. I'm just making sure that the contact is clean
and solid.)

Sometimes the trimmer capacitors (the screws on the main tuning
capacitor) will degrade and become intermittent. I've never been able
to develop a log term solution for that one. Sometimes, I can
temporarily improve the situation by injecting cleaner and rotating
them, but the problem usually returns. (You should not do this, unless
you are prepared to tweak the alignment) The whiskers will return in a
few years, but you can blow them out again.

-----------------------------------------------------------
spam:
wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13 (Barry Mann)
[sorry about the puzzle, spammers are ruining my mailbox]
-----------------------------------------------------------

  #9   Report Post  
Barry Mann
 
Posts: n/a
Default Tuner repair pointers

In , on 04/21/04
at 05:14 PM, "Colin B." said:

[ ... ]

If I'm tuned to
my favorite station (93.7, CKUA!), it'll be fine for a while and then
disappear entirely. To retune it, I have to go to 94.1; and the tuning
capacitor sounds (and looks on the meters) NOISY when I turn it.


[ ... ]

In another reply, Mark has the right answer. If you look closely at the
tuning capacitor (the thing attached to the dial cord that looks like
an egg slicer) you'll see some very fine metal "whiskers" are shorting
the plates together. This is a standard mid-life crisis for analog
tuners.

When you blow out the whiskers, take care not to bend anything in the
general area and don't turn any of the screws.

I'll also use a tiny drop of contact cleaner at each of the bearings.
(This is not an attempt to lubricate or clean the bearings. The
japanese use a little clip beside each bearing to make good contact
with the moving vane. I'm just making sure that the contact is clean
and solid.)

Sometimes the trimmer capacitors (the screws on the main tuning
capacitor) will degrade and become intermittent. I've never been able
to develop a log term solution for that one. Sometimes, I can
temporarily improve the situation by injecting cleaner and rotating
them, but the problem usually returns. (You should not do this, unless
you are prepared to tweak the alignment) The whiskers will return in a
few years, but you can blow them out again.

-----------------------------------------------------------
spam:
wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13 (Barry Mann)
[sorry about the puzzle, spammers are ruining my mailbox]
-----------------------------------------------------------

  #10   Report Post  
Karl Uppiano
 
Posts: n/a
Default Tuner repair pointers


"Mark D. Zacharias" wrote in message
...
Blow out the tuning capacitor with a compressor. Fairly common problem.
Naturally happens more towards the lower end of the scale, since this is
where the tuning capacitor's vanes are fully meshing.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Colin B." wrote in message
...
Hey all;

Next on my agenda is to fix up an old but fantastic tuner I have here;
a Pioneer TX-9800.

Now I'm not looking at doing a full alignment--that can be left for the
professionals. However the major problem seems like it should be easily
fixable. Basically, the tuning jumps around terribly. If I'm tuned to
my favorite station (93.7, CKUA!), it'll be fine for a while and then
disappear entirely. To retune it, I have to go to 94.1; and the tuning
capacitor sounds (and looks on the meters) NOISY when I turn it.

Any pointers? Once I get it out of my rack, I'm going to look for crap
on the tuning cap, but beyond that, I'm not sure.

Thanks!
Colin


Interesting problem. I have a Heathkit AJ-1214 AM/FM stereo tuner and a
matching AA-1214 amplifier that I built in 1974 that still look and work
like new, in continuous 24x7 use. Played LOUD all through high school and
college. Too bad the Heath Company went out of business. They made some
great stuff.




  #11   Report Post  
Karl Uppiano
 
Posts: n/a
Default Tuner repair pointers


"Mark D. Zacharias" wrote in message
...
Blow out the tuning capacitor with a compressor. Fairly common problem.
Naturally happens more towards the lower end of the scale, since this is
where the tuning capacitor's vanes are fully meshing.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Colin B." wrote in message
...
Hey all;

Next on my agenda is to fix up an old but fantastic tuner I have here;
a Pioneer TX-9800.

Now I'm not looking at doing a full alignment--that can be left for the
professionals. However the major problem seems like it should be easily
fixable. Basically, the tuning jumps around terribly. If I'm tuned to
my favorite station (93.7, CKUA!), it'll be fine for a while and then
disappear entirely. To retune it, I have to go to 94.1; and the tuning
capacitor sounds (and looks on the meters) NOISY when I turn it.

Any pointers? Once I get it out of my rack, I'm going to look for crap
on the tuning cap, but beyond that, I'm not sure.

Thanks!
Colin


Interesting problem. I have a Heathkit AJ-1214 AM/FM stereo tuner and a
matching AA-1214 amplifier that I built in 1974 that still look and work
like new, in continuous 24x7 use. Played LOUD all through high school and
college. Too bad the Heath Company went out of business. They made some
great stuff.


  #12   Report Post  
Karl Uppiano
 
Posts: n/a
Default Tuner repair pointers


"Mark D. Zacharias" wrote in message
...
Blow out the tuning capacitor with a compressor. Fairly common problem.
Naturally happens more towards the lower end of the scale, since this is
where the tuning capacitor's vanes are fully meshing.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Colin B." wrote in message
...
Hey all;

Next on my agenda is to fix up an old but fantastic tuner I have here;
a Pioneer TX-9800.

Now I'm not looking at doing a full alignment--that can be left for the
professionals. However the major problem seems like it should be easily
fixable. Basically, the tuning jumps around terribly. If I'm tuned to
my favorite station (93.7, CKUA!), it'll be fine for a while and then
disappear entirely. To retune it, I have to go to 94.1; and the tuning
capacitor sounds (and looks on the meters) NOISY when I turn it.

Any pointers? Once I get it out of my rack, I'm going to look for crap
on the tuning cap, but beyond that, I'm not sure.

Thanks!
Colin


Interesting problem. I have a Heathkit AJ-1214 AM/FM stereo tuner and a
matching AA-1214 amplifier that I built in 1974 that still look and work
like new, in continuous 24x7 use. Played LOUD all through high school and
college. Too bad the Heath Company went out of business. They made some
great stuff.


  #13   Report Post  
Karl Uppiano
 
Posts: n/a
Default Tuner repair pointers


"Mark D. Zacharias" wrote in message
...
Blow out the tuning capacitor with a compressor. Fairly common problem.
Naturally happens more towards the lower end of the scale, since this is
where the tuning capacitor's vanes are fully meshing.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Colin B." wrote in message
...
Hey all;

Next on my agenda is to fix up an old but fantastic tuner I have here;
a Pioneer TX-9800.

Now I'm not looking at doing a full alignment--that can be left for the
professionals. However the major problem seems like it should be easily
fixable. Basically, the tuning jumps around terribly. If I'm tuned to
my favorite station (93.7, CKUA!), it'll be fine for a while and then
disappear entirely. To retune it, I have to go to 94.1; and the tuning
capacitor sounds (and looks on the meters) NOISY when I turn it.

Any pointers? Once I get it out of my rack, I'm going to look for crap
on the tuning cap, but beyond that, I'm not sure.

Thanks!
Colin


Interesting problem. I have a Heathkit AJ-1214 AM/FM stereo tuner and a
matching AA-1214 amplifier that I built in 1974 that still look and work
like new, in continuous 24x7 use. Played LOUD all through high school and
college. Too bad the Heath Company went out of business. They made some
great stuff.


  #14   Report Post  
Colin B.
 
Posts: n/a
Default Tuner repair pointers

Barry Mann wrote:

In another reply, Mark has the right answer. If you look closely at the
tuning capacitor (the thing attached to the dial cord that looks like
an egg slicer) you'll see some very fine metal "whiskers" are shorting
the plates together. This is a standard mid-life crisis for analog
tuners.


Pretty much what I expected. I wasn't sure about whiskers (I'd heard
about them long ago, but couldn't remember in what context), but I
was (and am) expecting something shorting the plates.

I'll also use a tiny drop of contact cleaner at each of the bearings.
(This is not an attempt to lubricate or clean the bearings. The
japanese use a little clip beside each bearing to make good contact
with the moving vane. I'm just making sure that the contact is clean
and solid.)


Good point--thanks!

Sometimes the trimmer capacitors (the screws on the main tuning
capacitor) will degrade and become intermittent. I've never been able
to develop a log term solution for that one. Sometimes, I can
temporarily improve the situation by injecting cleaner and rotating
them, but the problem usually returns. (You should not do this, unless
you are prepared to tweak the alignment) The whiskers will return in a
few years, but you can blow them out again.


So what DOES cause the whiskers to grow? And is there any hope of
aligning a tuner with typical bench equipment (DVM, scope, signal
generator)?

Thanks,
Colin
  #15   Report Post  
Colin B.
 
Posts: n/a
Default Tuner repair pointers

Barry Mann wrote:

In another reply, Mark has the right answer. If you look closely at the
tuning capacitor (the thing attached to the dial cord that looks like
an egg slicer) you'll see some very fine metal "whiskers" are shorting
the plates together. This is a standard mid-life crisis for analog
tuners.


Pretty much what I expected. I wasn't sure about whiskers (I'd heard
about them long ago, but couldn't remember in what context), but I
was (and am) expecting something shorting the plates.

I'll also use a tiny drop of contact cleaner at each of the bearings.
(This is not an attempt to lubricate or clean the bearings. The
japanese use a little clip beside each bearing to make good contact
with the moving vane. I'm just making sure that the contact is clean
and solid.)


Good point--thanks!

Sometimes the trimmer capacitors (the screws on the main tuning
capacitor) will degrade and become intermittent. I've never been able
to develop a log term solution for that one. Sometimes, I can
temporarily improve the situation by injecting cleaner and rotating
them, but the problem usually returns. (You should not do this, unless
you are prepared to tweak the alignment) The whiskers will return in a
few years, but you can blow them out again.


So what DOES cause the whiskers to grow? And is there any hope of
aligning a tuner with typical bench equipment (DVM, scope, signal
generator)?

Thanks,
Colin


  #16   Report Post  
Colin B.
 
Posts: n/a
Default Tuner repair pointers

Barry Mann wrote:

In another reply, Mark has the right answer. If you look closely at the
tuning capacitor (the thing attached to the dial cord that looks like
an egg slicer) you'll see some very fine metal "whiskers" are shorting
the plates together. This is a standard mid-life crisis for analog
tuners.


Pretty much what I expected. I wasn't sure about whiskers (I'd heard
about them long ago, but couldn't remember in what context), but I
was (and am) expecting something shorting the plates.

I'll also use a tiny drop of contact cleaner at each of the bearings.
(This is not an attempt to lubricate or clean the bearings. The
japanese use a little clip beside each bearing to make good contact
with the moving vane. I'm just making sure that the contact is clean
and solid.)


Good point--thanks!

Sometimes the trimmer capacitors (the screws on the main tuning
capacitor) will degrade and become intermittent. I've never been able
to develop a log term solution for that one. Sometimes, I can
temporarily improve the situation by injecting cleaner and rotating
them, but the problem usually returns. (You should not do this, unless
you are prepared to tweak the alignment) The whiskers will return in a
few years, but you can blow them out again.


So what DOES cause the whiskers to grow? And is there any hope of
aligning a tuner with typical bench equipment (DVM, scope, signal
generator)?

Thanks,
Colin
  #17   Report Post  
Colin B.
 
Posts: n/a
Default Tuner repair pointers

Barry Mann wrote:

In another reply, Mark has the right answer. If you look closely at the
tuning capacitor (the thing attached to the dial cord that looks like
an egg slicer) you'll see some very fine metal "whiskers" are shorting
the plates together. This is a standard mid-life crisis for analog
tuners.


Pretty much what I expected. I wasn't sure about whiskers (I'd heard
about them long ago, but couldn't remember in what context), but I
was (and am) expecting something shorting the plates.

I'll also use a tiny drop of contact cleaner at each of the bearings.
(This is not an attempt to lubricate or clean the bearings. The
japanese use a little clip beside each bearing to make good contact
with the moving vane. I'm just making sure that the contact is clean
and solid.)


Good point--thanks!

Sometimes the trimmer capacitors (the screws on the main tuning
capacitor) will degrade and become intermittent. I've never been able
to develop a log term solution for that one. Sometimes, I can
temporarily improve the situation by injecting cleaner and rotating
them, but the problem usually returns. (You should not do this, unless
you are prepared to tweak the alignment) The whiskers will return in a
few years, but you can blow them out again.


So what DOES cause the whiskers to grow? And is there any hope of
aligning a tuner with typical bench equipment (DVM, scope, signal
generator)?

Thanks,
Colin
  #18   Report Post  
unitron
 
Posts: n/a
Default Tuner repair pointers

"Mark D. Zacharias" wrote in message ...
Blow out the tuning capacitor with a compressor. Fairly common problem.
Naturally happens more towards the lower end of the scale, since this is
where the tuning capacitor's vanes are fully meshing.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Colin B." wrote in message
...
Hey all;

Next on my agenda is to fix up an old but fantastic tuner I have here;
a Pioneer TX-9800.

Now I'm not looking at doing a full alignment--that can be left for the
professionals. However the major problem seems like it should be easily
fixable. Basically, the tuning jumps around terribly. If I'm tuned to
my favorite station (93.7, CKUA!), it'll be fine for a while and then
disappear entirely. To retune it, I have to go to 94.1; and the tuning
capacitor sounds (and looks on the meters) NOISY when I turn it.

Any pointers? Once I get it out of my rack, I'm going to look for crap
on the tuning cap, but beyond that, I'm not sure.

Thanks!
Colin


Vacuum instead of blow, and use a paint brush with long, soft
bristles (natural preferable to synthetic, less chance of static build
up) to knock the dust and stuff off the capacitor's plates into the
vacuum's airstream. Brush the dust out of the rest of the tuner while
you're at it.
  #19   Report Post  
unitron
 
Posts: n/a
Default Tuner repair pointers

"Mark D. Zacharias" wrote in message ...
Blow out the tuning capacitor with a compressor. Fairly common problem.
Naturally happens more towards the lower end of the scale, since this is
where the tuning capacitor's vanes are fully meshing.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Colin B." wrote in message
...
Hey all;

Next on my agenda is to fix up an old but fantastic tuner I have here;
a Pioneer TX-9800.

Now I'm not looking at doing a full alignment--that can be left for the
professionals. However the major problem seems like it should be easily
fixable. Basically, the tuning jumps around terribly. If I'm tuned to
my favorite station (93.7, CKUA!), it'll be fine for a while and then
disappear entirely. To retune it, I have to go to 94.1; and the tuning
capacitor sounds (and looks on the meters) NOISY when I turn it.

Any pointers? Once I get it out of my rack, I'm going to look for crap
on the tuning cap, but beyond that, I'm not sure.

Thanks!
Colin


Vacuum instead of blow, and use a paint brush with long, soft
bristles (natural preferable to synthetic, less chance of static build
up) to knock the dust and stuff off the capacitor's plates into the
vacuum's airstream. Brush the dust out of the rest of the tuner while
you're at it.
  #20   Report Post  
unitron
 
Posts: n/a
Default Tuner repair pointers

"Mark D. Zacharias" wrote in message ...
Blow out the tuning capacitor with a compressor. Fairly common problem.
Naturally happens more towards the lower end of the scale, since this is
where the tuning capacitor's vanes are fully meshing.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Colin B." wrote in message
...
Hey all;

Next on my agenda is to fix up an old but fantastic tuner I have here;
a Pioneer TX-9800.

Now I'm not looking at doing a full alignment--that can be left for the
professionals. However the major problem seems like it should be easily
fixable. Basically, the tuning jumps around terribly. If I'm tuned to
my favorite station (93.7, CKUA!), it'll be fine for a while and then
disappear entirely. To retune it, I have to go to 94.1; and the tuning
capacitor sounds (and looks on the meters) NOISY when I turn it.

Any pointers? Once I get it out of my rack, I'm going to look for crap
on the tuning cap, but beyond that, I'm not sure.

Thanks!
Colin


Vacuum instead of blow, and use a paint brush with long, soft
bristles (natural preferable to synthetic, less chance of static build
up) to knock the dust and stuff off the capacitor's plates into the
vacuum's airstream. Brush the dust out of the rest of the tuner while
you're at it.


  #21   Report Post  
unitron
 
Posts: n/a
Default Tuner repair pointers

"Mark D. Zacharias" wrote in message ...
Blow out the tuning capacitor with a compressor. Fairly common problem.
Naturally happens more towards the lower end of the scale, since this is
where the tuning capacitor's vanes are fully meshing.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
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"Colin B." wrote in message
...
Hey all;

Next on my agenda is to fix up an old but fantastic tuner I have here;
a Pioneer TX-9800.

Now I'm not looking at doing a full alignment--that can be left for the
professionals. However the major problem seems like it should be easily
fixable. Basically, the tuning jumps around terribly. If I'm tuned to
my favorite station (93.7, CKUA!), it'll be fine for a while and then
disappear entirely. To retune it, I have to go to 94.1; and the tuning
capacitor sounds (and looks on the meters) NOISY when I turn it.

Any pointers? Once I get it out of my rack, I'm going to look for crap
on the tuning cap, but beyond that, I'm not sure.

Thanks!
Colin


Vacuum instead of blow, and use a paint brush with long, soft
bristles (natural preferable to synthetic, less chance of static build
up) to knock the dust and stuff off the capacitor's plates into the
vacuum's airstream. Brush the dust out of the rest of the tuner while
you're at it.
  #22   Report Post  
Barry Mann
 
Posts: n/a
Default Tuner repair pointers

In , on 04/22/04
at 09:55 PM, "Colin B." said:

[ ... ]

So what DOES cause the whiskers to grow? And is there any hope of
aligning a tuner with typical bench equipment (DVM, scope, signal
generator)?


[ ... ]

It's a metallurgical problem, crystal growth. Some alloys do it, some
don't. I don't understand why they use that alloy in tuning capacitors.
They knew about this problem at least by the 50's, maybe earlier. I've
heard some concern that the new lead free solders may have this
problem. (won't that be fun)

-----------------------------------------------------------
spam:
wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13 (Barry Mann)
[sorry about the puzzle, spammers are ruining my mailbox]
-----------------------------------------------------------

  #23   Report Post  
Barry Mann
 
Posts: n/a
Default Tuner repair pointers

In , on 04/22/04
at 09:55 PM, "Colin B." said:

[ ... ]

So what DOES cause the whiskers to grow? And is there any hope of
aligning a tuner with typical bench equipment (DVM, scope, signal
generator)?


[ ... ]

It's a metallurgical problem, crystal growth. Some alloys do it, some
don't. I don't understand why they use that alloy in tuning capacitors.
They knew about this problem at least by the 50's, maybe earlier. I've
heard some concern that the new lead free solders may have this
problem. (won't that be fun)

-----------------------------------------------------------
spam:
wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13 (Barry Mann)
[sorry about the puzzle, spammers are ruining my mailbox]
-----------------------------------------------------------

  #24   Report Post  
Barry Mann
 
Posts: n/a
Default Tuner repair pointers

In , on 04/22/04
at 09:55 PM, "Colin B." said:

[ ... ]

So what DOES cause the whiskers to grow? And is there any hope of
aligning a tuner with typical bench equipment (DVM, scope, signal
generator)?


[ ... ]

It's a metallurgical problem, crystal growth. Some alloys do it, some
don't. I don't understand why they use that alloy in tuning capacitors.
They knew about this problem at least by the 50's, maybe earlier. I've
heard some concern that the new lead free solders may have this
problem. (won't that be fun)

-----------------------------------------------------------
spam:
wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13 (Barry Mann)
[sorry about the puzzle, spammers are ruining my mailbox]
-----------------------------------------------------------

  #25   Report Post  
Barry Mann
 
Posts: n/a
Default Tuner repair pointers

In , on 04/22/04
at 09:55 PM, "Colin B." said:

[ ... ]

So what DOES cause the whiskers to grow? And is there any hope of
aligning a tuner with typical bench equipment (DVM, scope, signal
generator)?


[ ... ]

It's a metallurgical problem, crystal growth. Some alloys do it, some
don't. I don't understand why they use that alloy in tuning capacitors.
They knew about this problem at least by the 50's, maybe earlier. I've
heard some concern that the new lead free solders may have this
problem. (won't that be fun)

-----------------------------------------------------------
spam:
wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13 (Barry Mann)
[sorry about the puzzle, spammers are ruining my mailbox]
-----------------------------------------------------------



  #26   Report Post  
Colin B.
 
Posts: n/a
Default Tuner repair pointers

Karl Uppiano wrote:

Interesting problem. I have a Heathkit AJ-1214 AM/FM stereo tuner and a
matching AA-1214 amplifier that I built in 1974 that still look and work
like new, in continuous 24x7 use. Played LOUD all through high school and
college. Too bad the Heath Company went out of business. They made some
great stuff.


Hmm. Once I've got all of my 'main' gear back together, I've got an
ancient AA-14 amp to try to restore. It works marginally, but is far
from healthy. Interestingly, there's a tuner that matches it, and it
seems to be behaving flawlessly.

  #27   Report Post  
Colin B.
 
Posts: n/a
Default Tuner repair pointers

Karl Uppiano wrote:

Interesting problem. I have a Heathkit AJ-1214 AM/FM stereo tuner and a
matching AA-1214 amplifier that I built in 1974 that still look and work
like new, in continuous 24x7 use. Played LOUD all through high school and
college. Too bad the Heath Company went out of business. They made some
great stuff.


Hmm. Once I've got all of my 'main' gear back together, I've got an
ancient AA-14 amp to try to restore. It works marginally, but is far
from healthy. Interestingly, there's a tuner that matches it, and it
seems to be behaving flawlessly.

  #28   Report Post  
Colin B.
 
Posts: n/a
Default Tuner repair pointers

Karl Uppiano wrote:

Interesting problem. I have a Heathkit AJ-1214 AM/FM stereo tuner and a
matching AA-1214 amplifier that I built in 1974 that still look and work
like new, in continuous 24x7 use. Played LOUD all through high school and
college. Too bad the Heath Company went out of business. They made some
great stuff.


Hmm. Once I've got all of my 'main' gear back together, I've got an
ancient AA-14 amp to try to restore. It works marginally, but is far
from healthy. Interestingly, there's a tuner that matches it, and it
seems to be behaving flawlessly.

  #29   Report Post  
Colin B.
 
Posts: n/a
Default Tuner repair pointers

Karl Uppiano wrote:

Interesting problem. I have a Heathkit AJ-1214 AM/FM stereo tuner and a
matching AA-1214 amplifier that I built in 1974 that still look and work
like new, in continuous 24x7 use. Played LOUD all through high school and
college. Too bad the Heath Company went out of business. They made some
great stuff.


Hmm. Once I've got all of my 'main' gear back together, I've got an
ancient AA-14 amp to try to restore. It works marginally, but is far
from healthy. Interestingly, there's a tuner that matches it, and it
seems to be behaving flawlessly.

  #30   Report Post  
Colin B.
 
Posts: n/a
Default Tuner repair pointers

Barry Mann wrote:
In , on 04/22/04
at 09:55 PM, "Colin B." said:

[ ... ]
So what DOES cause the whiskers to grow? And is there any hope of
aligning a tuner with typical bench equipment (DVM, scope, signal
generator)?

[ ... ]

It's a metallurgical problem, crystal growth. Some alloys do it, some
don't. I don't understand why they use that alloy in tuning capacitors.
They knew about this problem at least by the 50's, maybe earlier. I've
heard some concern that the new lead free solders may have this
problem. (won't that be fun)


Oh joy. As if the problems with lead-free solder weren't significant enough
already!

Regardless, blowing out the tuning capacitor fixed up the tuner beautifully!
Better than I expected, in fact; the tuning dial offset (93.7 appeared at
94.1) disappeared, which makes me think that it might not need an alignment
at all.

Thanks!
Colin


  #31   Report Post  
Colin B.
 
Posts: n/a
Default Tuner repair pointers

Barry Mann wrote:
In , on 04/22/04
at 09:55 PM, "Colin B." said:

[ ... ]
So what DOES cause the whiskers to grow? And is there any hope of
aligning a tuner with typical bench equipment (DVM, scope, signal
generator)?

[ ... ]

It's a metallurgical problem, crystal growth. Some alloys do it, some
don't. I don't understand why they use that alloy in tuning capacitors.
They knew about this problem at least by the 50's, maybe earlier. I've
heard some concern that the new lead free solders may have this
problem. (won't that be fun)


Oh joy. As if the problems with lead-free solder weren't significant enough
already!

Regardless, blowing out the tuning capacitor fixed up the tuner beautifully!
Better than I expected, in fact; the tuning dial offset (93.7 appeared at
94.1) disappeared, which makes me think that it might not need an alignment
at all.

Thanks!
Colin
  #32   Report Post  
Colin B.
 
Posts: n/a
Default Tuner repair pointers

Barry Mann wrote:
In , on 04/22/04
at 09:55 PM, "Colin B." said:

[ ... ]
So what DOES cause the whiskers to grow? And is there any hope of
aligning a tuner with typical bench equipment (DVM, scope, signal
generator)?

[ ... ]

It's a metallurgical problem, crystal growth. Some alloys do it, some
don't. I don't understand why they use that alloy in tuning capacitors.
They knew about this problem at least by the 50's, maybe earlier. I've
heard some concern that the new lead free solders may have this
problem. (won't that be fun)


Oh joy. As if the problems with lead-free solder weren't significant enough
already!

Regardless, blowing out the tuning capacitor fixed up the tuner beautifully!
Better than I expected, in fact; the tuning dial offset (93.7 appeared at
94.1) disappeared, which makes me think that it might not need an alignment
at all.

Thanks!
Colin
  #33   Report Post  
Colin B.
 
Posts: n/a
Default Tuner repair pointers

Barry Mann wrote:
In , on 04/22/04
at 09:55 PM, "Colin B." said:

[ ... ]
So what DOES cause the whiskers to grow? And is there any hope of
aligning a tuner with typical bench equipment (DVM, scope, signal
generator)?

[ ... ]

It's a metallurgical problem, crystal growth. Some alloys do it, some
don't. I don't understand why they use that alloy in tuning capacitors.
They knew about this problem at least by the 50's, maybe earlier. I've
heard some concern that the new lead free solders may have this
problem. (won't that be fun)


Oh joy. As if the problems with lead-free solder weren't significant enough
already!

Regardless, blowing out the tuning capacitor fixed up the tuner beautifully!
Better than I expected, in fact; the tuning dial offset (93.7 appeared at
94.1) disappeared, which makes me think that it might not need an alignment
at all.

Thanks!
Colin
  #34   Report Post  
unitron
 
Posts: n/a
Default Tuner repair pointers

"Colin B." wrote in message ...
Barry Mann wrote:
In , on 04/22/04
at 09:55 PM, "Colin B." said:

[ ... ]
So what DOES cause the whiskers to grow? And is there any hope of
aligning a tuner with typical bench equipment (DVM, scope, signal
generator)?

[ ... ]

It's a metallurgical problem, crystal growth. Some alloys do it, some
don't. I don't understand why they use that alloy in tuning capacitors.
They knew about this problem at least by the 50's, maybe earlier. I've
heard some concern that the new lead free solders may have this
problem. (won't that be fun)


Oh joy. As if the problems with lead-free solder weren't significant enough
already!

Regardless, blowing out the tuning capacitor fixed up the tuner beautifully!
Better than I expected, in fact; the tuning dial offset (93.7 appeared at
94.1) disappeared, which makes me think that it might not need an alignment
at all.

Thanks!
Colin


If that thing's old enough to have a dial cord then you can usually
tune in a a station, secure the knob to keep it from turning, and move
the dial indicator along the cord until it's at the spot on the dial
corresponding to that station's frequency. If the other stations show
up at the right place on the dial you're home free. It's only when
reception band is "wider" or "narrower" than the width of the dial
that alignment is usually called for and if it's not too far off it's
probably best to leave well enough alone (even though leaving well
enough alone is not a concept with which I've had a lot of practical
experience :-).
  #35   Report Post  
unitron
 
Posts: n/a
Default Tuner repair pointers

"Colin B." wrote in message ...
Barry Mann wrote:
In , on 04/22/04
at 09:55 PM, "Colin B." said:

[ ... ]
So what DOES cause the whiskers to grow? And is there any hope of
aligning a tuner with typical bench equipment (DVM, scope, signal
generator)?

[ ... ]

It's a metallurgical problem, crystal growth. Some alloys do it, some
don't. I don't understand why they use that alloy in tuning capacitors.
They knew about this problem at least by the 50's, maybe earlier. I've
heard some concern that the new lead free solders may have this
problem. (won't that be fun)


Oh joy. As if the problems with lead-free solder weren't significant enough
already!

Regardless, blowing out the tuning capacitor fixed up the tuner beautifully!
Better than I expected, in fact; the tuning dial offset (93.7 appeared at
94.1) disappeared, which makes me think that it might not need an alignment
at all.

Thanks!
Colin


If that thing's old enough to have a dial cord then you can usually
tune in a a station, secure the knob to keep it from turning, and move
the dial indicator along the cord until it's at the spot on the dial
corresponding to that station's frequency. If the other stations show
up at the right place on the dial you're home free. It's only when
reception band is "wider" or "narrower" than the width of the dial
that alignment is usually called for and if it's not too far off it's
probably best to leave well enough alone (even though leaving well
enough alone is not a concept with which I've had a lot of practical
experience :-).


  #36   Report Post  
unitron
 
Posts: n/a
Default Tuner repair pointers

"Colin B." wrote in message ...
Barry Mann wrote:
In , on 04/22/04
at 09:55 PM, "Colin B." said:

[ ... ]
So what DOES cause the whiskers to grow? And is there any hope of
aligning a tuner with typical bench equipment (DVM, scope, signal
generator)?

[ ... ]

It's a metallurgical problem, crystal growth. Some alloys do it, some
don't. I don't understand why they use that alloy in tuning capacitors.
They knew about this problem at least by the 50's, maybe earlier. I've
heard some concern that the new lead free solders may have this
problem. (won't that be fun)


Oh joy. As if the problems with lead-free solder weren't significant enough
already!

Regardless, blowing out the tuning capacitor fixed up the tuner beautifully!
Better than I expected, in fact; the tuning dial offset (93.7 appeared at
94.1) disappeared, which makes me think that it might not need an alignment
at all.

Thanks!
Colin


If that thing's old enough to have a dial cord then you can usually
tune in a a station, secure the knob to keep it from turning, and move
the dial indicator along the cord until it's at the spot on the dial
corresponding to that station's frequency. If the other stations show
up at the right place on the dial you're home free. It's only when
reception band is "wider" or "narrower" than the width of the dial
that alignment is usually called for and if it's not too far off it's
probably best to leave well enough alone (even though leaving well
enough alone is not a concept with which I've had a lot of practical
experience :-).
  #37   Report Post  
unitron
 
Posts: n/a
Default Tuner repair pointers

"Colin B." wrote in message ...
Barry Mann wrote:
In , on 04/22/04
at 09:55 PM, "Colin B." said:

[ ... ]
So what DOES cause the whiskers to grow? And is there any hope of
aligning a tuner with typical bench equipment (DVM, scope, signal
generator)?

[ ... ]

It's a metallurgical problem, crystal growth. Some alloys do it, some
don't. I don't understand why they use that alloy in tuning capacitors.
They knew about this problem at least by the 50's, maybe earlier. I've
heard some concern that the new lead free solders may have this
problem. (won't that be fun)


Oh joy. As if the problems with lead-free solder weren't significant enough
already!

Regardless, blowing out the tuning capacitor fixed up the tuner beautifully!
Better than I expected, in fact; the tuning dial offset (93.7 appeared at
94.1) disappeared, which makes me think that it might not need an alignment
at all.

Thanks!
Colin


If that thing's old enough to have a dial cord then you can usually
tune in a a station, secure the knob to keep it from turning, and move
the dial indicator along the cord until it's at the spot on the dial
corresponding to that station's frequency. If the other stations show
up at the right place on the dial you're home free. It's only when
reception band is "wider" or "narrower" than the width of the dial
that alignment is usually called for and if it's not too far off it's
probably best to leave well enough alone (even though leaving well
enough alone is not a concept with which I've had a lot of practical
experience :-).
  #38   Report Post  
Colin B.
 
Posts: n/a
Default Tuner repair pointers

unitron wrote:

If that thing's old enough to have a dial cord then you can usually
tune in a a station, secure the knob to keep it from turning, and move
the dial indicator along the cord until it's at the spot on the dial
corresponding to that station's frequency. If the other stations show
up at the right place on the dial you're home free. It's only when
reception band is "wider" or "narrower" than the width of the dial
that alignment is usually called for and if it's not too far off it's
probably best to leave well enough alone (even though leaving well
enough alone is not a concept with which I've had a lot of practical
experience :-).


Well as I said, blowing out the tuning capacitor cleaned everything
up almost miraculously. It is now a rock solid, steady, correctly-reading
(at any frequency across the dial) GORGEOUS sounding tuner. No adjustment
or alignment or even cleaning (the inside of the chassis was almost
pristine) needed at all. Dang, eh? :-)

Colin
  #39   Report Post  
Colin B.
 
Posts: n/a
Default Tuner repair pointers

unitron wrote:

If that thing's old enough to have a dial cord then you can usually
tune in a a station, secure the knob to keep it from turning, and move
the dial indicator along the cord until it's at the spot on the dial
corresponding to that station's frequency. If the other stations show
up at the right place on the dial you're home free. It's only when
reception band is "wider" or "narrower" than the width of the dial
that alignment is usually called for and if it's not too far off it's
probably best to leave well enough alone (even though leaving well
enough alone is not a concept with which I've had a lot of practical
experience :-).


Well as I said, blowing out the tuning capacitor cleaned everything
up almost miraculously. It is now a rock solid, steady, correctly-reading
(at any frequency across the dial) GORGEOUS sounding tuner. No adjustment
or alignment or even cleaning (the inside of the chassis was almost
pristine) needed at all. Dang, eh? :-)

Colin
  #40   Report Post  
Colin B.
 
Posts: n/a
Default Tuner repair pointers

unitron wrote:

If that thing's old enough to have a dial cord then you can usually
tune in a a station, secure the knob to keep it from turning, and move
the dial indicator along the cord until it's at the spot on the dial
corresponding to that station's frequency. If the other stations show
up at the right place on the dial you're home free. It's only when
reception band is "wider" or "narrower" than the width of the dial
that alignment is usually called for and if it's not too far off it's
probably best to leave well enough alone (even though leaving well
enough alone is not a concept with which I've had a lot of practical
experience :-).


Well as I said, blowing out the tuning capacitor cleaned everything
up almost miraculously. It is now a rock solid, steady, correctly-reading
(at any frequency across the dial) GORGEOUS sounding tuner. No adjustment
or alignment or even cleaning (the inside of the chassis was almost
pristine) needed at all. Dang, eh? :-)

Colin
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