Hello,

i'm an happy owner of a quad fm1 tube tuner.
It sounded marvelous despite being a mono tuner.

One month ago it started to fail.

At the beginning it worked few hours when i turned it on and then
stopped suddenly : no sound coming out.

Then it worked few minutes and now it doesn't work at all.
Sometimes when i turn it on it works few seconds, if i change the radio
it stops working.
The two lights on the front are always lighted when there is no sound
coming out. Before they worked ok.

First i thought it was the tubes that were dead, so i changed all.
No improvements.

Now i think it can be a dead capacitor, but there are 48, so witch one
is dead ?

I don't want to rebuild it completely since things are so small it will
be a pain to do it.

I have a multimeter and oscilloscope.

Is there someone that can guide me to repair it ?

Thank you,
Best regards,
Luc D.

a écrit dans le message de news:
...
Hello,

i'm an happy owner of a quad fm1 tube tuner.
It sounded marvelous despite being a mono tuner.

One month ago it started to fail.

At the beginning it worked few hours when i turned it on and then
stopped suddenly : no sound coming out.

Then it worked few minutes and now it doesn't work at all.
Sometimes when i turn it on it works few seconds, if i change the radio
it stops working.
The two lights on the front are always lighted when there is no sound
coming out. Before they worked ok.

First i thought it was the tubes that were dead, so i changed all.
No improvements.

Now i think it can be a dead capacitor, but there are 48, so witch one
is dead ?

I don't want to rebuild it completely since things are so small it will
be a pain to do it.

I have a multimeter and oscilloscope.

Is there someone that can guide me to repair it ?

Thank you,
Best regards,
Luc D.

Hi Luc !

I suggest you try to obtain the schemo and check some voltages at first !
Sorry for being so short !

Yves.

Fortulately, i have the complete documentation (scematic,...).
Ok, i can check some voltage, but start with what ?

a écrit dans le message de news:
...
Fortulately, i have the complete documentation (scematic,...).
Ok, i can check some voltage, but start with what ?

Start with PSU of course !
And post the schemo along with voltages at all tubes terminals.
This may help !

Yves.

Here it is :
http://cjoint.com/?fsk4p2hgkg

I don't know how fm tube tuner works but i have all information on this
one (maintenance documentation).

and here is the circuit description :

http://cjoint.com/?fslcThfHyX

In article .com,
says...

Hello,

i'm an happy owner of a quad fm1 tube tuner.
It sounded marvelous despite being a mono tuner.

One month ago it started to fail.

At the beginning it worked few hours when i turned it on and then
stopped suddenly : no sound coming out.

Then it worked few minutes and now it doesn't work at all.
Sometimes when i turn it on it works few seconds, if i change the radio
it stops working.
The two lights on the front are always lighted when there is no sound
coming out. Before they worked ok.

First i thought it was the tubes that were dead, so i changed all.
No improvements.

Now i think it can be a dead capacitor, but there are 48, so witch one
is dead ?

I don't want to rebuild it completely since things are so small it will
be a pain to do it.

I have a multimeter and oscilloscope.

Is there someone that can guide me to repair it ?

Thank you,
Best regards,
Luc D.

wrote:

Fortulately, i have the complete documentation (scematic,...).
Ok, i can check some voltage, but start with what ?


Hi Luc:


The first thing that you should measure is the voltage to ground from
each side of resistor R24. Quad do not publish the expected voltages in
their service data, but you should see approximately 300 volts (250-250)
on the side of the resistor that connects tp Pin 4 of PL2, and you will
probably see between 150 and 250 volts on the side of the resistor that
connects to electrolytic capacitor C38. If the voltage on the C38 side
of R24 is very low or zero, then you have one or more of the following
problems:

1) Open resistor R24.
2) Shorted capacitor C38.
3) Shorted capacitor C11.

If the voltages on each side of R24 check out, then it's time to start
checking the voltages at the plates and screen grids of V1, V3, V4 and
V5. First of all, make sure that all tube filaments are lit. Each tube
should be slightly warm after a few minutes of operation. Plate
voltages of V1, V3 and V4 will be very close to the voltage you measured
on the C38 side of R24, while the screen voltages will be considerably
lower (probably 65-125 volts). The plate and screen voltages for V5
will be much lower. Also check cathode voltages of V1, V3 and V4. They
should measure no more than 1 volt or so. Also check plate voltages on
both halves of V2. If you don't find anything obvious, then it's time to
do some signal tracing, for which you will need an FM signal generator
and a 'scope.

If this tuner still has all of its original capacitors and if these are
tubular capacitors in plastic cases, you will note that many of them are
probably cracked, if your tuner is typical, and all should be replaced.
So should the electrolytics. To replace the tubular capacitors, you
should use 500 volt rated disk ceramics, except for C33 which should be
a good quality film cap such as polypropylene. The working space is
tight, but the disk ceramics will fit if you take care. I've restored
many of these tuners in exactly this way. Make sure to keep all
capacitor leads as short as possible.

This isn't much, but it's a start...hope that you find your problem.
BTW, I believe that Quad in the UL still support this tuner, at least
they still did a couple of years ago, so it is worth getting in touch
with them if you don't arrive at a solution.

Best regards : Doug Bannard

Many thank's Doug,
I print your advices and will study them this evening.
It's great to find experts like you are in this topic.

Unfortunately i have no FM signal generator. I hope i can work without
it.
I have a scope and a multimeter.

I have already checked that the filaments lights.

I'll keep you informed of the results of my investigations,
BR,
Luc D.

wrote in message
oups.com...
Many thank's Doug,
I print your advices and will study them this evening.
It's great to find experts like you are in this topic.

Unfortunately i have no FM signal generator. I hope i can work without
it.
I have a scope and a multimeter.

I have already checked that the filaments lights.

I'll keep you informed of the results of my investigations,
BR,
Luc D.

OK, so you have the circuit diagram but don't know how to read it...and you
are obviously guessing about everything else.
FM Tuners are not the sort of thing anyone should be trying to fix without
the right tools and the requisite technical skills. Unfortunately you have
appear to have neither the tools or the skills.
But there is a solution - parcel it up and send it to Quad Service Dept. in
UK. They will sort it out PROPERLY and quickly and it won't cost you a
fortune.

Ok Mike, thank you for your great help ;-)

To send a thing like that will cost me at least 20=80 to go to quad and
20=80 to come back and somethin like 100=80 or 200=80 euros for the
repair.
And for me 150=80 euros is not nothing.

BR,
Luc D.

Here is what they have told me on UK.REC.AUDIO :

"You may well be able to do this if you can follow circuit diagrams
etc.
Do a search for Quadworld I think it was and all the Quad sites, the
circuit for the FM1 is on there. These things aren't rocket science and

in fact it'd be easier to mend this that any modern tuner "

wrote in message
oups.com...
Ok Mike, thank you for your great help ;-)

To send a thing like that will cost me at least 20? to go to quad and
20? to come back and somethin like 100? or 200? euros for the
repair.
And for me 150? euros is not nothing.

BR,
Luc D.

***Why don't you e-mail Quad Service and ask them the cost to repair the
FM1??? Contact . I think they have a standard charge
of about UKP 45.00 which is about 65 Euros.

wrote in message :

Here is what they have told me on UK.REC.AUDIO :

"You may well be able to do this if you can follow circuit diagrams etc.
Do a search for Quadworld I think it was and all the Quad sites, the circuit
for the FM1 is on there. These things aren't rocket science and in fact it'd
be easier to mend this that any modern tuner "

***The key point being that first sentence and I don't believe you have the
skills.
Speaking from experience in servicing hifi equipment, I get very annoyed
when someone brings me a Tuner/Amp/Control Unit etc that they have
endevoured to fix and failed, and then expect me to sort out their mess. It
ends up costing them 3 or 4 times as much to sort out as I always have to
work out & "undo' what has been done - before actually fixing the problem! I
much prefer to receive the faulty device 'untouched' by the customer as at
least then I can focus on the original fault condition.
At the end of the day it's your Tuner and if you want to mess with the
innards then feel free to do so. But don't moan when you have to pay through
the nose to get it sorted properly.

Hello everybody and in particular Doug,

Ah... it is so nice to be on holidays.
So much time to do things we never have time to do.

So it took this day to repair/rebuild my quad fm1, challenged i was by
Mike to repair it... ;-))

And yes, luckily this time i am, the force is with me (star wars is
coming back here this week), it works.

So i checked all voltages around R24 (333V - 211V), and then checked
all the voltages R2 (207V), R3 (205V), R4 (122V), R6 (72V), R10 (127V),
R8(177V), R13(97V), R17 (13V).

I also checked the cathode woltages of V1, V2, V3, V4, no shorcut or
open resistor.

Also i measured all those resistors and they seem to be honestly ok.

As my tuner worked few hours i suspected bad capacitors.

I checked C38 (8mfd), no shortcut, no open capacitor, and it seems to
play its role ok.

As adviced by Mike the 'Hunts' black capacitors are cracked (i can see
two of them cracked) so i replaced them all (11, 0.04mfd, 0.012mfd,
0.01mfd, 0.001mfd) by plastic ones, at least rated 400V (small
polystyren i think, i will source good ones later). They fit ok becase
they are very small. It was not too difficult to do.

It remains the left part of the tune (V1 and V2) i had not the time to
do it today.

Do you think that i have to replace also the grey transparent
capacitors (27p, 22p,...) ? same question for the white ones (2X
1000PFD)?

Now i'm listening to it and it works ok.

I confess that on the left side of the band reception is not perfect.
But i still have work to do.

I'll continue to rebuild it and keep you informed.

Best regards,
Luc D.

One detail : my quad FM1 serial number is 9351 and i have the circuit
diagram of 19062 and above. And there are few differences, it would be
great if by chance someone had the correct one.

See you,
Luc.

wrote:

Hello everybody and in particular Doug,

Ah... it is so nice to be on holidays.
So much time to do things we never have time to do.

So it took this day to repair/rebuild my quad fm1, challenged i was by
Mike to repair it... ;-))

And yes, luckily this time i am, the force is with me (star wars is
coming back here this week), it works.

So i checked all voltages around R24 (333V - 211V), and then checked
all the voltages R2 (207V), R3 (205V), R4 (122V), R6 (72V), R10 (127V),
R8(177V), R13(97V), R17 (13V).

I also checked the cathode woltages of V1, V2, V3, V4, no shorcut or
open resistor.

Also i measured all those resistors and they seem to be honestly ok.

As my tuner worked few hours i suspected bad capacitors.

I checked C38 (8mfd), no shortcut, no open capacitor, and it seems to
play its role ok.

As adviced by Mike the 'Hunts' black capacitors are cracked (i can see
two of them cracked) so i replaced them all (11, 0.04mfd, 0.012mfd,
0.01mfd, 0.001mfd) by plastic ones, at least rated 400V (small
polystyren i think, i will source good ones later). They fit ok becase
they are very small. It was not too difficult to do.

It remains the left part of the tune (V1 and V2) i had not the time to
do it today.

Do you think that i have to replace also the grey transparent
capacitors (27p, 22p,...) ? same question for the white ones (2X
1000PFD)?

Now i'm listening to it and it works ok.

I confess that on the left side of the band reception is not perfect.
But i still have work to do.

I'll continue to rebuild it and keep you informed.

Best regards,
Luc D.


Hi Luc:


I'm glad to hear that your tuner is now working again. Do not change
any of the low value capacitors 27pF, 22pF etc or any of the capacitors
that look like little ceramic tubes with a wire wrapped around each
end. If you disturb these, even by moving them a bit, you risk throwing
the tuner out of alignment. Just continue changing any of the "Hunts"
that you have not already changed and that should be sufficient.

After all of these years your tuner does probably need an alignment to
maximize its performance, but this is something that can only be done
with the right equipment as you will see from reading the Alignment
Instructions in the service manual. If you don't have it already, the
complete manual can be downloaded at :

http://iquebec.ifrance.com/quadfranc...s/manuels.html


Schematics can be found on this site as well.


Best regards : Doug Bannard

Hi Doug,

Ok i follow your advices. I don't touch to those.

I double checked my work this morning and discovered 2 errors (0.02 in
place of 0.002mfd and 0.04 in place of 0.004mfd).
Now it sings again great !

Thank you for the link for the manual. I was looking for the early
version of the diagram, but no matters, now it works great.

I don't touch also to the alignment as i think this is really a
specialist job.

I'm doing the listening phase, so nice to hear the radio again, i can
discover new music. It changes from my ever listened CDs.

Thank you and have a nice day,
Luc D.