Panasonic VP-8191A

Workshop Project #47 - Panasonic VP-8191A

From my pile of "reasonably priced eBay found" test gear: A Panasonic AM/FM radio test signal generator. It is the semi modern equivalent of the tube based solution from the last video. This one has a freely programmable frequency with AM or FM modulation on top. The output signal can be set to an almost invisible level, so the input antenna circuits of a device under test can be connected directly to the output. I tried measuring the output with my usual scope... nope. More noise on the connecting wire than there is signal. If you need to go that low, a fully shielded signal path is a must. The unit I have had nothing particular wrong with it, but I took the usual recapping approach. Maybe not necessary, maybe it was... especially the power supply caps had some visible liquid stains underneath which may or may not have been electrolyte... I do sleep much better now that it has the new caps! The buffer battery for the preset memory was absolutely up for a replacement though. No question about that. Other than these items, I took care of the case and made it nice and presentable again. Two casualties on the way: the power switch rod had a connector that broke - OpenSCAD to the rescue! - and the mains fuse holder was glued in place and didn't take kind to my attempts of removing it. But these are bog standard, so no problem either.


0:00 Intro / Overview / First look inside
2:40 First "Can" Removal / "Hard Lines" / Second "Can"...
3:40 First Peek / Output Attenuator / Power Supply
4:45 Front Panel Disassembly
6:02 Rear Panel and Whoops! / Washing Day!
7:55 Cover Plate Painting / Epoxy Glue Parts / OpenSCAD...
8:54 Inside: Attenuator, RF Generator
10:03 Inside: CPU and Counter / Recapping!
10:55 Recapping: PSU / Thermal Paste
13:05 Recapping Impressions: CPU, Control, RF Generator and Counter PCBs
14:09 Recapping and Cloing up: Attenuator / Keyboard Assembly
15:50 Front Panel Frame
16:45 Mounting: Handle, Case Frame, PSU Board
18:00 Mounting: Transformer, Rear Panel Components
20:13 Connecting Transformer / Adjusting PSU / Control PCB / Attenuator
21:29 Improvised Connections / First, Second and Third power up...
23:05 Finishing Assembly
24:52 New Battery / CPU "Can" Closing / Case Feet / Zip Ties
26:45 Overview...ish / Demo AM and FM
28:49 Connectivity Overview / Summary / Credits / Outtake

Music (in order)

My Train's A Comin' - Unicorn Heads
Nine Lives - Unicorn Heads
Wrong - Dan Henig
Town of 24 Bars - Unicorn Heads
Light Expanse - Unicorn Heads
(YouTube Audio Library)


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