RCA Model ??

Go down

RCA Model ??

Post by Patrick on Wed Sep 10, 2014 6:12 pm

I picked up an old RCA wooden radio that has no model number on it and I can't find any reference to it. I need the number to obtain a schematic and also to find out what one missing octal tube number is. The tubes I know are 6C6, 6D6, 43 and 25Z5. The radio is only 10" wide by 7 1/2" high and 6" deep. I don't know if I can post a picture here but if you send me your email I will send you a picture. Would anyone like to offer a guess as to the model?
Thanks for any help you can give me.

Patrick
Member
Member

Number of posts : 32
Registration date : 2010-11-08

Back to top Go down

Re: RCA Model ??

Post by Patrick on Wed Sep 10, 2014 7:15 pm


Patrick
Member
Member

Number of posts : 32
Registration date : 2010-11-08

Back to top Go down

Re: RCA Model ??

Post by willy3486 on Thu Sep 11, 2014 8:32 am

Do you have a picture of the insides of the radio? The chassis specifically. One way I use to find out models if it wasn't on it was to look in my riders in the sections for a model. My best guess is that it was made in the 30s ,maybe around 36 or so but that is a guess. Look through riders if you have them. If not post a photo of a chassis and maybe someone can look for you. I will pm you my email if you want to send photos for me. I will look and see if I can guess on it.

willy3486
Member
Member

Number of posts : 1424
Registration date : 2011-07-02

Back to top Go down

Re: RCA Model ??

Post by Patrick on Thu Sep 11, 2014 8:38 am


Patrick
Member
Member

Number of posts : 32
Registration date : 2010-11-08

Back to top Go down

Re: RCA Model ??

Post by Patrick on Thu Sep 11, 2014 11:11 am

The metal chassis plate states "Licensed under patents of Radio Corporation of America, General Electric Company, Westinghouse Electric & Mfg. Co., Hazeltine Corporation and associated companies, only for radio amateur, experimental and broadcast reception".† Chassis number 25-67021.† So it is not exclusively an RCA model.

Patrick
Member
Member

Number of posts : 32
Registration date : 2010-11-08

Back to top Go down

Re: RCA Model ??

Post by 35Z5 on Thu Sep 11, 2014 11:44 am

Patrick wrote:The metal chassis plate states "Licensed under patents of Radio Corporation of America, General Electric Company, Westinghouse Electric & Mfg. Co., Hazeltine Corporation and associated companies, only for radio amateur, experimental and broadcast reception".† Chassis number 25-67021.† So it is not exclusively an RCA model.

It not RCA at all but some independent mfgr that used circuits patented by RCA, GE, etc...
avatar
35Z5
Member
Member

Number of posts : 461
Registration date : 2008-03-12

Back to top Go down

Re: RCA Model ??

Post by Patrick on Thu Sep 11, 2014 11:50 am

It has tubes 6C6, 6D6, 43, 25Z5 and one unknown octal tube.† Any guesses as to what tube this is?

Patrick
Member
Member

Number of posts : 32
Registration date : 2010-11-08

Back to top Go down

Re: RCA Model ??

Post by 35Z5 on Thu Sep 11, 2014 1:15 pm

Probably a ballast, as the four tubes only add to 62v, so needs a resistor(inside ballast) to make up difference... Many different ballasts avail, voltage drop dependent on tube count in set...

BTW your type radio was common and known as a universal set, may or may not be any doc, schematic etc avail... You can put your tube line up in this finder and see what comes up...

http://www.grillecloth.com/sylvania/tubelist.php
avatar
35Z5
Member
Member

Number of posts : 461
Registration date : 2008-03-12

Back to top Go down

Re: RCA Model ??

Post by Wildcat445 on Thu Sep 11, 2014 1:19 pm

Let's see. †A 43 is audio output, 25Z5 the rectifier, 6C6 a converter, 6D6 probably the IF amplifier. †I would guess that the missing tube would be the second detector, avc and first audio tube, perhaps a 6Q7 or similar. †Perhaps Tom would have a better idea than this. †That looks a bit like a mystery Chicago radio chassis to me. †This is just a guess, an attempt to help, and is not guaranteed or even implied to be accurate. †Good luck.

Edit.......Oops. Tom was posting when I was. A ballast tube is a good guess. I never thought of that one.

WC

Wildcat445
Member
Member

Number of posts : 5164
Registration date : 2011-09-19

Back to top Go down

Re: RCA Model ??

Post by mr_ed01 on Thu Sep 11, 2014 3:59 pm

Its a TRF set, no IF, 6D6 RF amp, 6C6 detector, 25Z5 rect, 43 audio out.

mr_ed01
Member
Member

Number of posts : 99
Age : 74
Registration date : 2012-03-16

Back to top Go down

Re: RCA Model ??

Post by Wildcat445 on Fri Sep 12, 2014 1:17 am

If you are sure it is a TRF set, what make is it? It could be a superhet with the IF transformers under the chassis ala Crosley of that era. There has to be some type of resistance in the heater string to get rid of the extra voltage. The OP said that there was still another octal tube missing, making it a five tuber, right? Or have I read something incorrectly?

WC

Wildcat445
Member
Member

Number of posts : 5164
Registration date : 2011-09-19

Back to top Go down

Re: RCA Model ??

Post by willy3486 on Fri Sep 12, 2014 10:09 am

This may be one of the Allied kit radios. Maybe a knight. Check this link out. It almost looks like it.
Knight radio

IF you have a little time go to the allied catalogs page and look through the 1930s radios to see if you can find it. If so post it. The diagram may be hard to find but if it is in the catalog it may have a tube lineup listed.

Allied catalog page

willy3486
Member
Member

Number of posts : 1424
Registration date : 2011-07-02

Back to top Go down

Re: RCA Model ??

Post by 35Z5 on Fri Sep 12, 2014 11:33 am

mr_ed01 wrote:Its a TRF set, no IF, 6D6 RF amp, 6C6 detector, 25Z5 rect, 43 audio out.

Agreed, using the locator with these four tubes I got 248 hits(probably a fraction of actual sets), was a very popular configuration in the mid/late 30s... Dependent on whether it has a dial lamp or not ballast was probably a L49xx or L55xx, those are octal socket type... Sets listed without ballast probably had a curtain burner line cord...

http://www.grillecloth.com/sylvania/tubelist.php?comp=&mod=&Num=4&tube1=6d6&tube2=6c6&tube3=43&tube4=25z5&ball=&Submit=Submit&db=5
avatar
35Z5
Member
Member

Number of posts : 461
Registration date : 2008-03-12

Back to top Go down

Re: RCA Model ??

Post by Patrick on Fri Sep 12, 2014 12:47 pm




I don't know what a TRF set is.† The closest match I can find is to a Halson T5, T10 or T11.† The sharp tuning knob and the metal chassis ID plate are almost identical.† I still donít know what ballast tube to put in.† Iíll take a look at Allied Radio.

Patrick
Member
Member

Number of posts : 32
Registration date : 2010-11-08

Back to top Go down

Re: RCA Model ??

Post by Patrick on Fri Sep 12, 2014 12:50 pm


Patrick
Member
Member

Number of posts : 32
Registration date : 2010-11-08

Back to top Go down

Re: RCA Model ??

Post by willy3486 on Fri Sep 12, 2014 12:54 pm

Here is some info on the difference of a trf and superhet radio
trf vs superhet

When you look at allied I would probably look at 1939 and then go down. I bet that is where it came from.

willy3486
Member
Member

Number of posts : 1424
Registration date : 2011-07-02

Back to top Go down

Re: RCA Model ??

Post by Wildcat445 on Fri Sep 12, 2014 1:05 pm

TRF, in this case, stands for Tuned Radio Frequency. It was a type of radio chassis construction common-place before the introduction of the Superheterodyne circuit. There are no IF transformers in a TRF radio.

WC

Wildcat445
Member
Member

Number of posts : 5164
Registration date : 2011-09-19

Back to top Go down

Re: RCA Model ??

Post by 35Z5 on Fri Sep 12, 2014 1:06 pm

Could you post larger pict so the chassis & wiring detail can be seen???
avatar
35Z5
Member
Member

Number of posts : 461
Registration date : 2008-03-12

Back to top Go down

Re: RCA Model ??

Post by willy3486 on Fri Sep 12, 2014 2:34 pm

He sent the photos to me so I hope he doesn't if I post the bigger pics to help solve the mystery. When I got them I thought they kind of looked like a kit and then someone posted on facebook that it looked like the knight I posted a link to earlier. So my bet it is a knight. SO lets figure this out .


The radio front


The chassis from the top




The chassis underneath


willy3486
Member
Member

Number of posts : 1424
Registration date : 2011-07-02

Back to top Go down

Re: RCA Model ??

Post by 35Z5 on Fri Sep 12, 2014 3:36 pm

Jeez has no shortage of electrolytic caps, I see no less than five, should not be many sets with that tube line up and five electrolytics...

Also wiring is running from the octal socket to dial lamps, that socket is no doubt for a ballast...

I assume the two flying leads at end of chassis connect to the OPT, (transformer on speaker)???
avatar
35Z5
Member
Member

Number of posts : 461
Registration date : 2008-03-12

Back to top Go down

Re: RCA Model ??

Post by 35Z5 on Sat Sep 13, 2014 1:05 pm

With two dial lamps it probably used a L49 ballast with similar heater circuit to this radio.

http://www.nostalgiaair.org/PagesByModel/796/M0012796.pdf
avatar
35Z5
Member
Member

Number of posts : 461
Registration date : 2008-03-12

Back to top Go down

Re: RCA Model ??

Post by Patrick on Sun Sep 14, 2014 11:15 pm

We never figured out the make and model but I certainly got a lot of worthwhile information.† Thanks to willy3456 for re-posting my pictures and a thanks to 35Z5 for the schematic.† It certainly looks like my radio.† Now to decide whether to ebay out the radio as is or try to find a L49C ballast tube and restore it myself.† I don't usually work on pre 1940 chassis.
Thanks again to everyone.

Patrick
Member
Member

Number of posts : 32
Registration date : 2010-11-08

Back to top Go down

Re: RCA Model ??

Post by Sponsored content


Sponsored content


Back to top Go down

Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum