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42-1015 OLD FM BAND( BOL Cabinet) - Printable Version

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+--- Thread: 42-1015 OLD FM BAND( BOL Cabinet) (/showthread.php?tid=15255)


42-1015 OLD FM BAND( BOL Cabinet) - davidff - 08-19-2016

My 42-1015 has the old FM band that actually picks up some stations clearly at the left side of the old band.  The FM antenna that wraps around the cabinet used to connect I believe in the 4-prong spot near the middle of the back of the chassis.  Mine is not connected and I do not have the 2 'prong' receptacle to attach it.  How did this connect?  Did it connect one end of the antenna for signal, and the other a ground?  There are 4 openings, 2 top, 2 bottom on the input area.  It sounds louder when I put one of the wires into the left top opening.

I already have a Pilot that will work with the phono attachment, I just would like to have the old FM band play loud and clear on the 3 stations that it picks up which are actually now in the 102 area.

Any suggestions, comments are appreciated.

Thanks,

RE: 42-1015 OLD FM BAND( BOL Cabinet) - vecher - 08-19-2016

I have a 42-1012 that probably uses the same arrangement.. Here is a picture...

[Image: http://i292.photobucket.com/albums/mm38/wb4yvo/philco%2044%20010_zps0quqfz7x.jpg]

The old FM band I think was from 42-50 MHZ. So you should not be picking up anything on that.. Maybe a couple of 2 way radio signals but not the new FM from 88-108 Mhz.. Mine doesn't pick up anything...

Hope Diagram helps..

Skip...

RE: 42-1015 OLD FM BAND( BOL Cabinet) - Ron Ramirez - 08-19-2016

If you live near strong FM transmitters, very often it is easy to pick up harmonics of a portion of the modern FM band on the old 42-50 mc band...but the signals will usually be low in volume.

RE: 42-1015 OLD FM BAND( BOL Cabinet) - Kestas - 08-21-2016

I've owned my 42-1013 since 1978. I haven't fired it up in the last 25 years, but I remember listening to FM channels up to around 98. I'm perplexed why everyone says you can't pick anything up on the prewar FM dial. I understand the reasoning why they say you can't pick anything up, but confused to why I can. I can't wait to restore my unit and start listening to it again.

RE: 42-1015 OLD FM BAND( BOL Cabinet) - Joeztech - 10-28-2016

As Ron mentions, it is possible to pick up harmonics of the main current existing FM stations. Harmonics that are most likely to be picked up are half of the current frequency. For instance, if a station broadcasts on 99.5mHz it might appear at 49.75mHz on your radio. Divide the current frequency by 2 and you will have the likely frequency it shows up on your radio dial. I do not know if anyone ever made a converter to convert the 88-108mHz band back down to the 42-50mHz band. If there are any, such a converter would repopulate your FM band with lots of stations.

Joe

RE: 42-1015 OLD FM BAND( BOL Cabinet) - Sean - 10-28-2016

(10-28-2016, 05:04 PM)Joeztech Wrote:  I do not know if anyone ever made a converter to convert the 88-108mHz band back down to the 42-50mHz band. If there are any, such a converter would repopulate your FM band with lots of stations.

Joe

Hallicrafters made a few, Scott had one that could be mounted inside the cabinet of their receivers, and I'm sure other companies made them as well.  There are some shown on this page:

https://www.somerset.net/arm/fm_only_converters.html

The problem is the old band is 8 MHz wide while the modern band is 20 MHz wide.  The converter has to break up the new band into 3 segments to cover everything on the old band.

RE: 42-1015 OLD FM BAND( BOL Cabinet) - davidff - 11-02-2016

Good Morning,

I noticed that when I purchased  my 1015 it had hanging off the chassis that FM Nodel 1002A that shows in the hyperlink that you showed above.  Can you tell me how to hook this thing up to see if it actually still works? It is definitely the CRYSTAL DEVICES CO, unit that shows in the pictures.  Thanks for solving that mystery for me!
Dave

RE: 42-1015 OLD FM BAND( BOL Cabinet) - Radioroslyn - 11-02-2016

(11-02-2016, 09:41 AM)davidff Wrote:  Good Morning,

I noticed that when I purchased  my 1015 it had hanging off the chassis that FM Model 1002A that shows in the hyperlink that you showed above.  Can you tell me how to hook this thing up to see if it actually still works? It is definitely the CRYSTAL DEVICES CO, unit that shows in the pictures.  Thanks for solving that mystery for me!
Dave

Link??

Did see something that's interesting, https://www.somerset.net/arm/reprints/one_tube_converter_p1.gif
If you like to do some experimenting you could build it but just use L1, L2, C1, and the 1N34. Connect L1 to your FM ant though C1, diode anode and gnd to the Philco. Use an unmodulated signal from a signal generator across L2 @ 50mc. You can use the sg to tune across the new FM band or set the sg and use the Philco to tune most of the FM band (8mc)

RE: 42-1015 OLD FM BAND( BOL Cabinet) - Sean - 11-03-2016

(11-02-2016, 09:41 AM)davidff Wrote:  Good Morning,

I noticed that when I purchased  my 1015 it had hanging off the chassis that FM Nodel 1002A that shows in the hyperlink that you showed above.  Can you tell me how to hook this thing up to see if it actually still works? It is definitely the CRYSTAL DEVICES CO, unit that shows in the pictures.  Thanks for solving that mystery for me!
Dave

There is an article posted on that site that has some information about how it works and how to connect it to the radio.

https://www.somerset.net/arm/reprints/one_diode_fm_converter.gif

It uses the 2nd harmonic of the local oscillator of the receiver.  The oscillator would need to be de-tuned to cover the range but I'm still not sure if you will be able to cover the entire modern FM band on the 42-1015.  The dial range is 42.1-49.9 which is a span of 7.8 MHz.  There will be a little extra coverage at either end of the dial but I doubt it will be 2.2 MHz worth.