[[email protected]]

Hi all, calling all Nagra aficionados (or ex-aficionados)...

I hadn't used my Nagra IVS in several months and figured I'd take it
out of the drawer and put it through its paces. Powered it up and all
seems to work fine. Was playing back a test tape I had made on
another recorder and all well. I decided to record a test message on
both mic inputs, and although I can hear the sound very well when
monitoring off the mic pres, and modulometer is kicking up nicely,
there is nothing actually recording onto the tape. WHen I flip the
switch to monitor off the tape (while recording) there is nothing,
silence. Flipped the switches back and forth a few times, tried on
each channel, and same result. Pressed the reference oscillator while
recording and that's not getting on the tape either.

Any idea where I may look for the fault? Am I missing something
obvious? I have the service manual but not sure where to start (I'm
not an electronics repair guy, just a musician who loves old
recorders). I have been able to diagnose and solve a couple of
problems in the past (one was a bad capacitor that was preventing the
unit from powering on at all), but could use some help with this one
if you have suggestions.

Thanks!
--Robert

[Mike Rivers]

wrote:

I hadn't used my Nagra IVS in several months and figured I'd take it
out of the drawer and put it through its paces. Powered it up and all
seems to work fine. Was playing back a test tape I had made on
another recorder and all well. I decided to record a test message on
both mic inputs, and although I can hear the sound very well when
monitoring off the mic pres, and modulometer is kicking up nicely,
there is nothing actually recording onto the tape. WHen I flip the
switch to monitor off the tape (while recording) there is nothing,
silence. Flipped the switches back and forth a few times, tried on
each channel, and same result. Pressed the reference oscillator while
recording and that's not getting on the tape either.

Any idea where I may look for the fault?

The record amplifier or the bias oscillator, or maybe something as simple
as a broken head wire or a poor connection inside. But first, clean the
heads.
I would not recommend that you try to repair the Nagra yourself. They have
some things in there that aren't obvious or conventinal.



--
"Today's production equipment is IT based and cannot be operated without
a passing knowledge of computing, although it seems that it can be
operated without a passing knowledge of audio." - John Watkinson

[[email protected]]

On Mar 11, 8:24*pm, "Soundhaspriority" wrote:
wrote in message

...



Hi all, calling all Nagra aficionados (or ex-aficionados)...

I hadn't used my Nagra IVS in several months and figured I'd take it
out of the drawer and put it through its paces. *Powered it up and all
seems to work fine. *Was playing back a test tape I had made on
another recorder and all well. *I decided to record a test message on
both mic inputs, and although I can hear the sound very well when
monitoring off the mic pres, and modulometer is kicking up nicely,
there is nothing actually recording onto the tape. *WHen I flip the
switch to monitor off the tape (while recording) there is nothing,
silence. *Flipped the switches back and forth a few times, tried on
each channel, and same result. *Pressed the reference oscillator while
recording and that's not getting on the tape either.

Any idea where I may look for the fault? *Am I missing something
obvious? *I have the service manual but not sure where to start (I'm
not an electronics repair guy, just a musician who loves old
recorders). *I have been able to diagnose and solve a couple of
problems in the past (one was a bad capacitor that was preventing the
unit from powering on at all), but could use some help with this one
if you have suggestions.

Thanks!
*--Robert

I hesitate to comment when Scott Dorsey actually knows the machine, but I
don't think it could be the bias oscillator. If it were, the sound would be
highly distorted, but not completely absent.

The rotary switch is always on the list of suspects. You could try
exercising the switch; rotate back and forth many times. These switches
become intermittent in storage. Exercise removes dirt/oxide. Contact cleaner
may be useful.

Also, visually inspect for a broken head wire. Look for a tiny strand of
loose braid that may be shorting out the signal.

Bob Morein
(310) 237-6511

Hi all, wow that was quick, thanks!!

Bob gets the prize, it was the rotary switch! Rocked it back and
forth several times from one end stop to the other, powered the
machine on, and it records fine now! Whew... Now I'll give it a good
cleaning with contact cleaner for good measure.

I notice the take up reel tension roller wobbles a fair bit when tape
is engaged (until I steady it with my finger), so there might be an
adjustment required there, I'll look at the manual.

You guys may think I'm crazy, but I'm talking to a guy about buying
his 4.2. I love these old Nagras and I'd like to have a mono to keep
the stereo company in the drawer! Heck for $500 or so I think it's
great to own a working piece or recording history.

Thanks again, you guys are great!

--Robert

[Ian Bell[_2_]]

Mike Rivers wrote:
wrote:

I hadn't used my Nagra IVS in several months and figured I'd take it
out of the drawer and put it through its paces. Powered it up and all
seems to work fine. Was playing back a test tape I had made on
another recorder and all well. I decided to record a test message on
both mic inputs, and although I can hear the sound very well when
monitoring off the mic pres, and modulometer is kicking up nicely,
there is nothing actually recording onto the tape. WHen I flip the
switch to monitor off the tape (while recording) there is nothing,
silence. Flipped the switches back and forth a few times, tried on
each channel, and same result. Pressed the reference oscillator while
recording and that's not getting on the tape either.

Any idea where I may look for the fault?

The record amplifier or the bias oscillator, or maybe something as simple
as a broken head wire or a poor connection inside. But first, clean the
heads.
I would not recommend that you try to repair the Nagra yourself. They have
some things in there that aren't obvious or conventinal.




Do Nagras have a record link on a connector somewhere like the RevoX
A77? - that one caught me out several times.

Cheers

ian

[Scott Dorsey]

wrote:
Hi all, calling all Nagra aficionados (or ex-aficionados)...

I hadn't used my Nagra IVS in several months and figured I'd take it
out of the drawer and put it through its paces. Powered it up and all
seems to work fine. Was playing back a test tape I had made on
another recorder and all well. I decided to record a test message on
both mic inputs, and although I can hear the sound very well when
monitoring off the mic pres, and modulometer is kicking up nicely,
there is nothing actually recording onto the tape. WHen I flip the
switch to monitor off the tape (while recording) there is nothing,
silence. Flipped the switches back and forth a few times, tried on
each channel, and same result. Pressed the reference oscillator while
recording and that's not getting on the tape either.

Any idea where I may look for the fault? Am I missing something
obvious? I have the service manual but not sure where to start (I'm
not an electronics repair guy, just a musician who loves old
recorders). I have been able to diagnose and solve a couple of
problems in the past (one was a bad capacitor that was preventing the
unit from powering on at all), but could use some help with this one
if you have suggestions.

I'd check to make sure there is bias at the heads with a scope, then work
backwards from there. When these things get old, what mostly fails are
capacitors and switches, and switches are usually a matter of cleaning.

I suggest that if you haven't had it in for service for a while, you
might want to just send it to Dan Dugan for an annual cleaning and lineup.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

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On Mar 12, 9:14*am, (Scott Dorsey) wrote:

I'd check to make sure there is bias at the heads with a scope, then work
backwards from there. *When these things get old, what mostly fails are
capacitors and switches, and switches are usually a matter of cleaning.

I suggest that if you haven't had it in for service for a while, you
might want to just send it to Dan Dugan for an annual cleaning and lineup..
--scott

Hi Scott, and thanks! As I replied earlier, Bob's suggestion to rock
the main selector switch must have cleaned off the dirt or oxidation
on the contacts and it works now. Serves me right for not using it
more often! I'm up in Canada so would probably send it to Trew Audio
in Toronto for cleanup/alignment/service, but since I'm not a pro and
can't write off such expenses, I keep nursing it and keep it going.
It may not be 100% up to snuff, but sounds pretty darn good to my ears
anyway (for the occasional analog recording I do these days, more for
the fun, historical and hands-on aspect of it, than practicality, as
the digital gear I have is so much easier to use). Probably for a
similar reason that I own and use the Nagra (and an AG-440), I also
own and drive and maintain an 82 Benz diesel sedan in the summer - I
love that old-world engineering and the quality and longevity that
went into the fine products of that bygone era...

Cheers, all!
--Robert

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On Mar 12, 12:57*pm, (Scott Dorsey) wrote:
Get a can of DeOxit, then, and hit the rotary switch contacts with it.
The pots are sealed Type J ones, though, and they don't ever seem to go
noisy.

While you're at it, if that 440 is really a 440B, do the input/bias/repro
switches on those because they also go intermittent a lot with only occasional
use. * The pushbuttons on the 440C seem more reliable in that regard.
--scott

Will do, thanks!
Yeah, I powered up the 440 as well (figured I'd run a bit of current
through the old gear, warm up the caps a bit and get the motors
spinning for a while). I'm pretty sure the transport is a C but the
electronics are B's, and indeed the switches are noisy, as are the
level pots! Time for a Spring cleaning!! Gotta admire those old
440's, built like tanks. Why I hang onto that old gear I'm not all
that sure sometimes. I suppose I love to see those reels turning, and
the feel of tape in my hands, and oh yeah, I love the smell of head
cleaner in the morning! :-)