raypsi wrote:
Hey OM:

The only way to make that work is with a converter.
Back in the day before police scanners, I made a converter that
converted the 70cm police band down to the AM broadcast band. 530Khz
thru 1600Khz was the band back then. My converter could put 3 local
police frequencies on the AM band.
All the converter is is an LO, input tank circuit, and a mixer. The
only active component was the LO. I used a CB rock which were dirt
cheap. Caught the 70cm harmonic into the mixer, getting the police
band down to the AM band.

I made a version that plugged inline with the car antenna and the car
radio, that could be switched in and out.
I couldn't make enough of them, Was the best selling product I ever
made.

73 OM
de n8zu



On Jan 5, 5:17 pm, joeturn wrote:
On Dec 29 2009, 10:00 pm, Tim Shoppa wrote:

On Dec 29, 8:38 pm, Gene wrote:
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
Internally most of the good AM car radios I've met had mechanically
ganged slug tuning, although variable capacitor tuning existed too.
I once broadened the band of a Titan 4 reciever by
adding a varible capacitor with a spst it might need another varible
capacitor with a spdt to get the other end of the spectrum.



That's great if you're comfortable adjusting the mechanics of the
radio internally to get the tracking right. Remember, you won't be
broadening the tuning range, you'll be shifting the tuning range.
Tim N3QE


How did that work? Wasn't the police band using FM back then like they
do today? I suppose the RF signal may have had enough "AM" component
perhaps?