The PHILCO Phorum
48-482 rear panel help - Printable Version

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+--- Thread: 48-482 rear panel help (/showthread.php?tid=25730)


48-482 rear panel help - keithchip - 04-10-2025

I've recently finished the internal restoration of a locally purchased Philco 48-482. The cabinet is in ok shape except there is no rear panel.

All is working well and the radio is a good performer. The question is when to stop on the project? I kind of like the "well used" look of the cabinet and am reluctant to refinish. But I would like to have a somewhat realistic rear panel for safety purposes, and to add completeness. Can anyone supply a rear panel photo of a 48-482?

Then there's the question of where I use this radio? The most likely location is for garage entertainment while tinkering on other projects. Should I add a Bluetooth module so make the unit more versatile, or is this sacrilege? It's a moral dilemma!

Thanks in advance for any help with rear panel pictures.

   
   

RE: 48-482 rear panel help - GarySP - 04-10-2025

Welcome to the Phorum, keithchip! How far you take a radio on cabinet restoration is a matter of personal preference. Like you, I prefer the 'gently used' look. Several members here take their restorations to "fresh out of the box" condition, and I have no problem with that either. I don't believe the 48-482 came with a back cover, but I may be wrong. I've never seen a photograph with any back. Take care and BE HEALTHY! - Gary

RE: 48-482 rear panel help - klondike98 - 04-11-2025

Gary is correct, there was not a rear panel on the 48-482. I restored one of those and its a great sounding radio that recieves FM. Unfortunately the FM1000 tube that was unique to Philco and is required for the set is getting very hard to find.

RE: 48-482 rear panel help - keithchip - 04-11-2025

Thanks for the responses Gary and Bob. I'm a little surprised that there's no back panel - although I know older Philco's were that way. There's a slot in the cabinet at the rear that looks like it could be used to attach a panel - I may make something up to keep hands out.

I was lucky that I got the radio with an operational FM1000 tube - albeit rolling around in the back. The FM discriminator is working pretty well but it's a picky circuit to get to that point. I think my strategy would be to adapt the radio to something else (6BN6?) if the present FM1000 failed.

Many thanks!

RE: 48-482 rear panel help - jrblasde - 04-11-2025

Yes, I can confirm. I bought one (haven’t restored it yet) which didn’t have a back panel.

RE: 48-482 rear panel help - keithchip - 04-12-2025

Thanks Joseph. Hope you get to restore your 48-482 before too long!

RE: 48-482 rear panel help - Arran - 04-12-2025

I also have one of these, again it never had a back, and no trace of one. I have been told that the pushbuttons used to have clear plastic covers, which I though was interesting since other Philco models with similar pushbuttons do not. It's strange because the pushbuttons also have plastic covers over the station tabs like many others do, so it isn't obvious that they are missing anything.
Regards
Arran

RE: 48-482 rear panel help - Radioroslyn - 04-12-2025

Yup Arran is correct it is missing the pushbutton covers. I don't know where they all go but it's a common issue on this model. Had one back in the 70's It was complete. You might check w/are resource page under knob venders and see if any thing turns up.

Here's a link that will get you to some pics most w/cover and a few topless: https://www.radiomuseum.org/r/philco_48_482.html

RE: 48-482 rear panel help - 462ron - 04-12-2025

Hi Keith, here is an article that covers different FM detector circuits including a section on the theory and alignment of the FM1000!

https://www.radiomuseum.org/forumdata/users/4942/file/FM%20Alignment%20Ghirardi%201952%20OCR.pdf

Ron

RE: 48-482 rear panel help - klondike98 - 04-13-2025

There's a picture of one of the plastic covers in the following thread: https://philcoradio.com/phorum/showthread.php?tid=6752&pid=43067#pid43067

I bought a full set of them in 2012 or so from David Frush. His email is listed in the post but I don't know if he is still selling or would have any.

The 48-482 chassis is large enough and heavy enough that I found it easiest if I build a chassis stand to work on it. There are some available out there but this was my DIY version.
[Image: https://www.dropbox.com/scl/fi/wdcuvi5zocwl8j8wpqs5b/chassis_stand.jpg?rlkey=5yfu3kkt7rkn5ptqkk9x8ijkw&raw=1]

RE: 48-482 rear panel help - MrFixr55 - 04-14-2025

Hi Kettlechip and welcom to the Phorum.

The back panel question is interesting. I have quite a few radios that use power transformers, built around 1930 through 1949, which have no backs, as opposed to the transformerless AA5 style sets which almost always have backs and, in the case of newer postwar sets, have interlocks due to "hot chassis" design. The only transformer powered radio in my collection that does have a back panel (Other than my Radiolas which have a flip top lid and no interlock) is my RCA 1R91 "Livingston"

As to adding Bluetooth, one way around this is to add an "Aux" or "Phono" jack. This was often added by radio shops and the Zenith service docs in the mid 1930s had diagrams for the modifications. Generally the mod involves adding a SPDT switch, breaking the circuit at the input to the volume control (one "leg" of the resistor), connecting the volume control to the common or wiper of the switch. Connect the wire removed from the volume control to one "leg" of the switch. Connect the other "leg" to a jack for adding the audio source. According to the schematic, your radio should have an "aux in" jack already. It should be labeled Phone or TV, and the jack should be on the back panel. It may be that little pin jack on the rear right of the chassis but is unlabeled. On both the Philco Phorum Library and Nostalgia Air diagrams, the Jack is labeled J200 and the push button is PB10. What is interesting is that J200 is not switched. Apparently PB10 is designed to switch the audio output of the radio either to the volume control or to ground without switching the "aux / phono" jack. This is strange because a ceramic or crystal cartridge may load down the audio, affect frequency response or be driven by the signal.

RE: 48-482 rear panel help - keithchip - 04-14-2025

Many thanks to all for the responses!
No plastic button "covers" on my radio.
Ron, thanks for the chapter on FM alignment - fascinating stuff.
MrFixr55, thanks for your comments. I have used the J200 jack for testing purposes already and I think adding a Bluetooth module is pretty straightforward, but I'm not sure I will do that just yet.

RE: 48-482 rear panel help - GarySP - 04-17-2025

Hello keithchip. You could make a hardboard back for the set, but make sure you provide plenty of ventilation holes in the cover at the top and bottom it. The tubes in a compact set like this produce quite a bit of heat in operation. You want that heat to dissipate out of the cabinet. Just my observation. Take care. - Gary

RE: 48-482 rear panel help - jrblasde - 04-17-2025

The 48-482 is an AC only set as well, featuring a power transformer. While the transformer shouldn’t get “hot”, it is yet another (fairly sizable) source of heat. They certainly do get a bit warm under load.