EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: USMC_Spike on November 24, 2017, 11:47:34 pm
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I've had this VP-7635p for a couple of years now and have
repaired the front panel push lock switches so that it now works.
And you know the rest of the story, ebay purchase, that supposedly
it was working but w/o output. Who ever had it when "cleaning it"
broke the switches then tried to super glue them together.
When I opened it up for inspection, there was no burnt smell or
other component(s) which stood out that looked fried, burnt,
cracked, short, or cold broken solder joint that would stop
and output signal.
As I started to look closer at the input I realized the broke
off the switch holder and then super glued the switch to the frame.
I use some old dental pics to removed the super glue--
it resulted in the unit working.
Fast forward to today that I wanted to get the VP-7635p
a working calibration. Of course when I got it the front
panel calibration pot's, stickers had been removed and
I recall when I asked the guy before I bought it, he assured
me none of the pots were turned--Yeah right.
I'll look and asked in all the regular spots to see if any one
had a service manual, calibration manual, or a operator manual.
I found the operation manual for the VP7637A, which has
memory and other functions. They should be similar I think.
I also found some type of VP-7635A calibration procedure written in french.
I tried to write this procedure in English, using online translation.
These three manuals I've attached. I've hooked up the scope according to the
Section 8-1 "Phase Calibration of Pilot Signal" from the VP7637A.
I then tried to start on the VP7635a/p translation but I don't get any of the
images in that. P2. 2.2, 3, 3.1. I'm using a 100MHz Tek 2246 Mod 1 scope.
It doesn't go down to 10uV/sec. I get 20uV/sec. but the trace is in the upper
right quadrant of the scope.
I've tried turning the +, -, and mode pots, but cannot get proper
reading for + or - on the scope. That is I cannot get a +.2V out
along with a -.2V out. The mode pot kind of balances it out,
but either the + or - pot is turned to the max.
Let me post these manuals,
then I'll try to add a few pics to describe where I am.
I've never done this kind of set up and I'm sure with
the manual it would be simpler. I don't think that is going
to happen either. But I'll try with what I have.
Thanks,
USMC_Spike
The files were too large to upload.
I will try and upload them on at a time
or provide links to them.
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Here is part 1 of 2.
If it will load up.
It did.
The next part, I'll have to wait.
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Here might be part 2 if I had patience and waited for the time limit for posting.
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Here is the link to the Written in french Calibration screen shots.
I don't see the link button, so I'll paste it below (copy and paste in browser if needed:
http://marcel.cremmel.llc.free.fr/CouffignalTS2/Autoradio_files/VP_7635A.pdf (http://marcel.cremmel.llc.free.fr/CouffignalTS2/Autoradio_files/VP_7635A.pdf)
Here is a link to a different unit, but the pic of the face is good:
https://www.ackrutat-shop.de/kategorien/elektrotechnik-frequenzumwandler/sonstiges/1127/fm-multiplex-signalgenerator-messen-funk-panasonic-national-vp-7635a (https://www.ackrutat-shop.de/kategorien/elektrotechnik-frequenzumwandler/sonstiges/1127/fm-multiplex-signalgenerator-messen-funk-panasonic-national-vp-7635a)
Datasheet from Helmut:
http://repairmemo.my.coocan.jp/vp-7637a/panasonicvp7635a.pdf (http://repairmemo.my.coocan.jp/vp-7637a/panasonicvp7635a.pdf)
Thanks,
USMC_Spike
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bump