Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Closed
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Shortwave Converter
#1

Has anyone had any experience with an early thirties shortwave converter? I have a Deforest Crosley model 201B that has two tubes, a 27 and a 24A. It is almost identical to the Stewart Warner 301. What I am wondering is what is the output signal supposed to be or how would one determine it. It says nothing on the schematic.

Gregb


Attached Files
.pdf Deforest 855B.pdf Size: 212.56 KB  Downloads: 232
#2

I've got the sw unit but never have used  it. I would just listen for it's output on the bcb. Don't remember if the convertor's dial is calibrated in frequency or 1-100. If it's calibrated in frequency use a generator set at the convertor's dial frequency to determine the best sensitivity by tuning the bc dial. This insures that the rf and osc are tracking properly.
Or
Bcb dial frequency= convertor's dial frequency - it's local osc frequency. So if you set the convertor dial at 2.5mc and use a well calibrated SW receiver and find the osc output at 3.5mc your bc dial setting is going to be 1mc.

When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!

Terry
#3

Usually these 2 tube units have a detector (27) and an oscillator (24) for output.

While not exactly the same, I restored one of these and tested it in a rare Northland console last month:

http://www.russoldradios.com/blog/archives/11-2016

My conclusion was that this was an interesting accessory that was not very practical for everyday use and that had been demonstrated by an early repair in which they had fixed the radio and simply unhooked the SW adaptor. But they are fun to play with.

"I just might turn into smoke, but I feel fine"
http://www.russoldradios.com/
#4

Well I have been messing around with this thing for a while now and I do seem to get some reception if the radio is tuned to 1mc and then the converter seems to work though rather poorly. I put some signals into it from my signal generator and its fairly close but does not seem to be very sensitive. I think we will call this an interesting novelty.

Gregb




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco 91 Restore Code ??
Can someone tell me if my 42 tubes are connected triode or pentode in fixed or cathode bias? How could I tell by looking...dconant — 10:47 AM
Philco 40-120C Restoration
Hello David, that is great news about the tubes source being local ! Sounds like you got good start on the radio . ...radiorich — 09:41 AM
An attempt to remove the Field Coil from a G speaker
Mike; I've only run into a speaker with an open filed coil twice, and they were on newer speakers from the 1940s. One ...Arran — 12:48 AM
An attempt to remove the Field Coil from a G speaker
Arran Yes, this is my plan for now and what do I got to lose, this is not even the speaker from this radio, but one o...morzh — 10:44 PM
An attempt to remove the Field Coil from a G speaker
Mike;  I would unwrap the field coil, and see if maybe there a break near one of the ends, like where the coil wire att...Arran — 10:23 PM
An attempt to remove the Field Coil from a G speaker
...and this is what I did. I fed a little LT into the screwholes with a small brush, and a little on the rim next to the...morzh — 09:52 PM
Philco 40-120C Restoration
I combined the two 40-120C threads together as we like to keep the discussion of the same radio together. It helps with...klondike98 — 09:36 PM
Philco 40-120C Weak, Distorted Ouput
Just checked were I buy tubes price is four dollars. So living in Florid we have a local source for tubes. David    David — 09:14 PM
Philco 40-120C Weak, Distorted Ouput
The higher voltage may be due to higher mains voltage. My mains run 120-125AC when the set was new mains would be 110-11...David — 09:09 PM
Philco 40-120C Weak, Distorted Ouput
Thank you for your reply. I pulled a speaker from a Philco 41-221 and received the same result. I used a signal tracer t...bluecap — 08:45 PM

[-]
Who's Online
There are currently no members online.

>