A Cobra 2000GTL on 10 meters

[loosecannon]

Hi all,

Im celebrating 10-4 day by finishing up a fun project for someone.
They wanted a 2000GTL that covers the 10 meter band.
I've heard rumors that people used to do this to CB radios back in the day...

here's a few pics. i can take more.
(yes my bench is messy, what about it?!)



not quite done yet, but close!
LC

 

[nomadradio]

Between 40 and 45 years ago, a regular column appeared in 73 magazine called "CB to 10". Didn't contemplate the radio covering 11 meters any more, just putting a CB where it could be used above 28.3 MHz. Oddly enough, some of the first articles in the series were written by Bob Heil, now sk.

Whose 3-digit mod did you use? The australian guy?

Way cool mod.

73

 

[VMC]

Yes, we must know more about such wizardry

 

[loosecannon]

yes this is the digimax lite board with the MC145106 adapter board.
MB8719 won't get you up into 10 meters without a crystal change.

the board you see attached to the power supply bracket is a filter that cuts out the multiplexing noise.

i use a 7809 to drop the 13.8 volts from the radio down before i feed it to the digimax board as i think that much drop is a bit hard on the 7805 they use on it.
LC

 

[nomadradio]

a filter that cuts out the multiplexing noise.

A big step up, that. The shielding on the flat cables is, too. Learned to make sure the ends of the shield are insulated and can't touch chassis metal.

a 7809 to drop the 13.8 volts

Got in the habit of soldering the tab of a 7808T to the ground foil near the main filter cap. That, and a 10uf cap soldered to the output and gound leg of the chip.

Rockin' mod!

73

 

[loosecannon]

yes nomad those are good tips.

I took advice your advice about running the power and ground wires that feed the 7809 right to the main filter cap, and it seems to have worked quite well.

there still seem to be a few "birdies" on some freqs but i think this is just an artifact of the kit because ive never done one that didn't have at least a few.
LC