On Dec 28, 12:38�pm, Tim Shoppa wrote:
On Dec 27, 1:34�pm, Gene wrote:

Season`s greetings to all...
While in England in `91, I picked up a Ford motor car radio receiver.
P21 79GB-18K810 �HA . � Two band , LW & MW .. (166 KHz - 285 KHz LW
& �666KHz �- 1500Khz MW �+/- ) .I would like to extend the LW band as
high in frequency as i can , and the MW band as low as i can in
frequency..I.F. is 465 kHz...Object : To create a beacon ( 200KHz -
400 KHz ) receiver...
Is there anyone out there that has any experience , and or ideas with
what i have in mind ?

TIA � Gene � WB7NGI

If analog tuning then you add or remove capacitance to each LC and
hope that the padding can be adjusted or supplemented enough so that
everything (mixer and front end) tracks. It won't be so much
"extending" the tuning range but instead will be "shifting" the tuning
range.

If digital tuning then you'll have to locate the schematic for the PLL
chipset and see if you can convince the local oscillator to shift far
enough. With some PLL chipsets there are programming pins or diodes
that set the allowed range. In many cases, if you don't need the
original tuning range, you can patch in a divide by two or just change
the reference oscillator. If you change the reference oscillator then
the display won't be right but will be mathematically related to the
actual frequency.

I collect British tabletop radios and am quite familiar with their
longwave dial on tube-type analog sets (my favorite is when they do
not list frequencies but only wavelengths) but am not particularly
familiar with British car radios. My one piece of advice with respect
to car radios from foreign autos of 70's vintage or older, is to check
carefully WRT 6V or 12V and WRT to negative ground or positive ground.

Tim N3QE

Tim, thanks for the reply...analog...made in Canada....so i assume it
is a Philco-Ford , unable to find schematic , will have to do some
reverse engineering to to figure out what cap , is what

Thanks , Gene WB7NGI