Panasonic National,  VP-7635a/p calibration maintenance Asst, w/Questions  - Page 1
Forum section: electronics / testgear

author: USMC_Spike
author_rank: Regular Contributor
timestamp: November 24, 2017, 11:47:34 pm
content: I've had this VP-7635p for a couple of years now and haverepaired the front panel push lock switches so that it now works.And you know the rest of the story, ebay purchase, that supposedlyit 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 orother component(s) which stood out that looked fried, burnt,cracked, short, or cold broken solder joint that would stopand output signal.As I started to look closer at the input I realized the brokeoff 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-7635pa working calibration. Of course when I got it the frontpanel calibration pot's, stickers had been removed andI recall when I asked the guy before I bought it, he assuredme none of the pots were turned--Yeah right.I'll look and asked in all the regular spots to see if any onehad a service manual, calibration manual, or a operator manual.I found the operation manual for the VP7637A, which hasmemory 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 theSection 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 theimages 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 upperright quadrant of the scope.I've tried turning the +, -, and mode pots, but cannot get properreading for + or - on the scope. That is I cannot get a +.2V outalong 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 withthe manual it would be simpler. I don't think that is goingto happen either. But I'll try with what I have.Thanks,USMC_SpikeThe files were too large to upload.I will try and upload them on at a timeor provide links to them.

author: USMC_Spike
author_rank: Regular Contributor
timestamp: November 24, 2017, 11:59:41 pm
content: Here is part 1 of 2.If it will load up.It did.The next part, I'll have to wait.

author: USMC_Spike
author_rank: Regular Contributor
timestamp: November 25, 2017, 12:02:20 am
content: Here might be part 2 if I had patience and waited for the time limit for posting.

author: USMC_Spike
author_rank: Regular Contributor
timestamp: November 25, 2017, 12:06:14 am
content: 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.pdfHere 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-7635aDatasheet from Helmut:http://repairmemo.my.coocan.jp/vp-7637a/panasonicvp7635a.pdfThanks,USMC_Spike

author: USMC_Spike
author_rank: Regular Contributor
timestamp: March 05, 2018, 05:35:53 am
content: bump