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

new fm?
#1

Found this on a web site not sure if it means its converted the old fm to new?
Philco 42-350 uses the old FM band that goes from 42 MHz to 50 MHz. It is relatively easy to receive, more or less satisfactory, some of the stations in the modern 88 MHz to 108 MHz by simply detuning the local oscillator so that its second harmonic together with an incomming signal of the modern FM band produce an IF frequency of 4.3 MHz which is the IF frequency of the FM IF (Intermediate Frequency) transformers in this radio.

Can anyone explain if it does and how to do it? Thanks Doug
#2

Can you give us the link to the site where you found this? More info would be helpful.

--
Ron Ramirez
Ferdinand IN
#3

Here it is

http://antiqradio.com/post_philco-radio-...-1942.html
#4

Okay, 4.3 mc is the FM IF in the 42-350. The point the writer was trying to make is, some strong local FM stations can often be tuned in on these older FM receivers - not on their normal frequency, but by the local oscillator of the 42-350 beating with the second harmonic of the modern FM broadcast signal.

No adjustments need be made to the 42-350 to do this (other than a normal alignment of the entire radio after it is serviced, that is). These sets will pick up a few signals from the modern FM band - but only if you have very strong FM signals in your area. It will not pick up weak signals of the modern FM band because of this.

Oh, and I had a good laugh from that site's description of the 42-350's "peptode audio output." Icon_lol Is that something related to Pepto-Bismol?

--
Ron Ramirez
Ferdinand IN
#5

Ah ok now I see thanks Ron!
#6

(03-11-2012, 01:05 PM)fixinmyphilco Wrote:  Ah ok now I see thanks Ron!
If you are serious about trying to get this thing a pass a modern FM signal what you would have to do is replace or modify #7 ant coil to tune the FMBC band and then replace or modify the osc coil so it will tune the lo 4.3mc above the incoming fm signal. Like 92.3 to 112.3 then you'll be in business.
Terry

#7

check out the converters section of this website. Has sone info about how they did it after WWII

http://www.somerset.net/arm/fm_only.html

John
Las Vegas, NV USA
#8

(03-14-2012, 09:16 PM)LASJayhawk Wrote:  check out the converters section of this website. Has sone info about how they did it after WWII

http://www.somerset.net/arm/fm_only.html

Very cool thank you!




Users browsing this thread:
[-]
Recent Posts
Philco Model 38-7: what caps & resistors do fail typically?
Hi all, on vacation in Montreal,  a friend of mine showed me a Philco Model 38-7 console radio from the 30ies. Mechan...Musaeum — 07:21 PM
Part numbers to model cross
I looked thru the documents and did not see one. Might have missed it though.Jim Dutridge — 07:16 PM
Philco 42-345 Restoration/Repair
Please tell me this was it, I replaced resistor 27 and it's playing on the broadcast band. I am afraid to change the ban...osanders0311 — 06:12 PM
Philco 42-345 Restoration/Repair
So far still no broadcast, I am posting pictures of #14 Oscillator and also a resistor #27 which connects to an XXL tube...osanders0311 — 04:02 PM
Part numbers to model cross
I believe there is that document, and I think we might have it in the Library.morzh — 03:29 PM
Philco 42-345 Restoration/Repair
Ok MrFixr55,  I have tried the DeoxIT D5 on the band switch and even though it has relieved the tension I felt when turn...osanders0311 — 11:11 AM
Part numbers to model cross
Is there a reference somewhere where you can punch in Philco part numbers and see what models those parts were used in?Jim Dutridge — 10:17 AM
Philco 42-345 Restoration/Repair
Hi OSanders, Look carefully at the band switch. Turn it slowly and "wiggle" it around the desired band. ...MrFixr55 — 12:33 AM
5U4 vs 5Z4 tubes
I think that RCA and GE introduced metal tubes in the USA in 1936.  I don't know if they were being made by RCA, GE or b...MrFixr55 — 11:20 PM
Philco 42-345 Restoration/Repair
Vlad95, Thank you for the stringing guides and wow there are so manyosanders0311 — 06:01 PM

[-]
Who's Online
There are currently 968 online users. [Complete List]
» 1 Member(s) | 967 Guest(s)
Avatar

>