[gary rabbitt]

Hi guys, and Happy New year to all.
I hadn't bought any radios for a whilie now, being more choosey when they come along.
I hadn't been to the local Goodwill store in a couple of weeks, and I was going to drive right on past at frst, but decided to have a look just for fun.

While not a radio, I wanted you all to see what I found. On the counter was a Philco RP-1 ! At first, I thought it was just a standard turntable, but seein the Philco mane, and turning it over I seen it was something special, and I remembered the wireless capibility of this and other players.
At $19.99 (the oiriginal selling price when new) I decided to go ahead and get it. That pretty much made my day Check out the comment on the price tag about not being guaranteed


I am going to clean up the original finish and leave it as it is. Not sure about the cartridge will find out soon. Motor and transformer seem ok.

Chassis looks untouched, and I am now recapping it. I included a shot of the bottom label in case someone needs it, and I have a higher res scan if need be.


[Image: http://antiqueradios.com/gallery/d/82405-1/RP_a.JPG]

[Image: http://antiqueradios.com/gallery/d/82407-1/RP_b.JPG]

[Image: http://antiqueradios.com/gallery/d/82409-1/RP_c.JPG]

[Image: http://antiqueradios.com/gallery/d/82411-1/RP1d.JPG]

(In case someone needs a higher resolution scan, I have one. Cheaned up this tag in graphics program. 2 other under side labels on request.)

[Image: http://antiqueradios.com/gallery/d/82413-1/RP1Label.JPG]


Take care, Gary.

[Syl]

Nice find for a more than decent price!

You _know_ the cartridge is bad.

Syl

[scooby214]

That will be a nice turntable to display, even before you get it to work. Congrats!

[DeckApe]

I've never even _heard_ of an RP-1. That is awesome.

[Texasrocker]

Great find Gary! Congrats! You could also add a rca input to the transmitter, use a "Y" male rca connector to attach a tape deck or CD player ( stereo L & R to mono) if you wished. Add a 10' pc of wire to antenna and broadcast on AM into all your radios. What freq were those LPAM xmitters pre- set for?, or it may even be adjustable freq? Good luck with your restoration!!

[Ron Ramirez]

Randal

The RP-1, RP-2, et al. sets were designed to operate on the low end of the broadcast band, and the frequency can indeed be adjusted by the user.

DeckApe, please look through the 1939 through 1942 pages of the Philco Radio Gallery here on my site, and you will see a variety of Philco wireless phonographs.

And Gary, congrats on a nice find!

[Doug Houston]

That model was offered by Philco for 1941 and 1942. There was also a 41-RP-2, which had a lid on the cabinet to close while playing the records. As Ron has already said, those oscillators operated at the low end of ther AM band. The one you bought has had an antenna added to it, though it shouldn't be necessary. The Philco jobs coupled he output of the 6A7 into the AC line, and worked very well. The 42-RP-1 and a 42-RP-2, had slightly different cabinets, but the same players, otherwise. I have, or have had several wireless record players, and the Philco jobs are the best designed, and the best performing of any of them.

The 41-RP-2 that I have was owned by friends from new, and I have known it since then. It was used in their living room, with an old USR&T Radiotrope set, and worked like gangbusters. The RP-2 was replaced by a stereo phono, and they gave it to me. I seem to recall that he pickup cartridge was a high output type, but I'm not absolutely sure. Since I have a large 78 record collection, I use it once in a while.

[DeckApe]

Huh... well, whaddaya know. I learn something new every day. I'll have to spend a little more time poking around on your site--and looking at my RMS books from 1940-42.

[gary rabbitt]

Thanks guys,

Cabinet is polishing up well, I am not going to strip it. Rubber idler was in good shape. Platter needs a reflocking.

Syl, I know the cart is bad as most are of this type. Not sure what to do about it. (West Tech rebuild for a customer didn't sound right last year) The brand of cart says "American" on it, not sure if it's original, but fits in perfect.

The unit as Ron says tunes from about 530kc to 590kc.

I have recapped/ restuffed it already, and it sends out a clean carrier. I tried connecting a small mp3 player to the tone arm leads, and only a very weak sound is transmitted, at full volume of the player. I found a bad resistor,( 99k tested 160k) , and I'm going thru the others tonight. I figure not much can go wrong with these, maybe something I am overlooking.

One thing odd, the diagram showed two AC line caps in the filter block. 3903-DG (two .01s)
The block in the unit, looked factory installed was a 3903 SG (one .01) this wouldn't have anything to do with the sound issue though.

Anyhow, I will mess around and see if I can't get some sound transmitted tonight. Would the impedance be a big factor compared to the xtal cart, and trying to inject the output of an mp3 player cause no sound?

Take care , Gary

[Texasrocker]

You may want to try using a input line matching transformer to get the output signal from your mp3 balanced for max gain into the LPAM xmitter via its high-imp input from the old tonearm cartridge leads. Since most LPAM xmitters work better on the higher range of the band ( for more distance and better audio quality), you could also try subbing in another " fully adjustable " loop stick" type oscillator coil that would allow you to broadcast on a higher ( open in your area) frequency, but then again, other mods would be necessary as for antenna out as well since the orig design fed back into the ac line. AES has the fully adjustable BC Band loopsticks avail for cheap price. The addition of a longwire antenna will also help if you modify it. And also, the addition of a homebrew antenna-matching "pi-network" to feed the antenna output into a outdoor horizontal- "receiving type" antenna, and match the pi-network tuning cap to your broadcasting freq as set in your xmitter will get you max range and performance for LPAM broadcasting!
Unfortunately, using 530- 590 kc for LPAM transmitting is very limited at best for any distance other than across the room in my past experiences. You will need to get the input up to max (without distortion) ... you can add a 500K pot attenuator for input control if you wish for tape-deck/CD player(s) use,( or adjust your mp3 vol control high as possible without distortion) to acheive 100% full output modulation on the AM band. Still, that is a very nice vintage Philco find indeed!Have fun with your new vintage Philco LPAM transmitter!!

[Syl]

Syl, I know the cart is bad as most are of this type. Not sure what to do about it. (West Tech rebuild for a customer didn't sound right last year) The brand of cart says "American" on it, not sure if it's original, but fits in perfect.

Nothing has changed.

As for the cartridge, it is most probably the original. I have done many "American" cartridge -gold body- in the past
for similar phonos.

I have recapped/ restuffed it already, and it sends out a clean carrier. I tried connecting a small mp3 player to the tone arm leads, and only a very weak sound is transmitted, at full volume of the player.

You need a solid 3V to drive the transmitter. Anything below that will work but offer a weak signal and lots of noise.

You could replace with an 84T, rebuild the original (not that difficult) or use a modern ceramic cartridge and a
tiny transistor preamp using the cathode bias voltage of the input tube to feed the said preamp.
I've built a few preamps using surface mount transistors and resistors encapsulated in epoxy. The result
looks much like a post stamp with 3 tiny wires. I glued it right behind the volume pot with only one additional wire
going to the small chassis for the +Vcc. One wire goes to ground (via the pot's shell, one goes to the input
and the third one goes to +Vcc/pot). Gives a gain of around 4. Enough to drive this transmitter using
a 0,7V ceramic cartridge.

[Image: http://www.oldradioz.com/howto/preamp.jpg]

[Image: http://www.oldradioz.com/howto/smt_preamp_1.jpg]

[Image: http://www.oldradioz.com/howto/smt_preamp_2.jpg]

I use double side sticky tape for mounting the preamp to the pot.
Not the 4 wires on the prototype. The final version has only 3 wires from wich only
one goes to the chassis.

Syl

[billvet6]

Great find. All I ever find at the Goodwill and Salvation army are broke VCRs and obsolete computers.

[gary rabbitt]

Hi Guys,

Thanks Syl for the diagram of the little amp. I have never worked with those surface mount things but should be no problem. Looks very good and when encased you'd barely see it. I assume the transistor is any small signal NPN type? I have some of those, but they are not surface mount, they should work.
I think however, I may try and rebuild the original. I will need to read your tutorial again for specifics. Whether to remove the element from another cart, or try to get a crystal bar element would be the only decision. I may have a newer cart around here I wil have to check. I had bought some stuff from a closing electronics store, and I think there were some cartridges in the stuff. Opening the cart would not be a problem, so I may give it a try, why not?

The main goal on this player is to get it to play as is should. Not worried about adding another input as I think the range of these is not that great.
As for the coupling to the AC line, I can't see where it shows that in the diagram. The antenna symbol is all that's shown on the diagram. I know the carpet tacks and the wire inside this one does not look original.

Take care, and I will get back to to you on what I find.
Gary.

[Ron Ramirez]

Don't worry, folks...the posts dealing with religion have not disappeared...I have split those posts into a new topic which may be found at Old Ron's Bar & Grill, appropriately entitled "Let's Discuss Religion," so that we may continue discussing Gary's RP-1 in this thread.

[Ron Ramirez]

Doug Houston made the following comments regarding Gary's RP-1, which were moved over to the "religion" topic by me only because I did not see an option here to split a post in two. Sorry, Doug. Here's his reply:

Gary: look back at one of my posts about the function of this player. remember that i said (or at least alluded) to the fact, that Philco didn't use an antenna wire on these players. They coupled the output oif the 6A7 into the line, as a "carrier current" transmission. A lot of the other companies' wireless players did use an antenna line, either dropped to the floor, or as a third condustor in the line cord. The Philco players played very nicely throughout the house, because the wiring in the house carried the signal. Further, an antenna wire on the output of the oscillator will swing its frequency when a person comes near to it. It literally detunes the oscillator.