EMRFD Message Archive 77

Message Date From Subject
77 2006-08-05 18:52:00 kenk1zyw ARRL Challenge
The DC RX and DSB/CW TX is the tack I have been playing with. Have you
priced new double sided circuit board lately? Between it and a vfo
suitable variable cap.... well there goes the budget

de Ken K1UM

PS
I just joined and so I am the newbe for today... I've read Wes's book
cover to cover and think its the best thing since sliced bread..

Thanks Wes....
78 2006-08-06 05:24:48 Shawn Upton Re: ARRL Challenge
Although I am hoping to do a PCB for it, I am *not*
planning on the PCB to be in the $50 project. I'm
guessing around $10 for the PCB (in quantity), perhaps
less; but a simple 5x6 or so single sided PCB for dead
bugging the radio should be plenty cheap (again in
quantity).

No fancy variable cap; they are really nice and the
best way to go IMO: but you're right: expensive! I'll
probably do a high voltage zener, as a varactor tuned
circuit; but I will probably use a two pin jumper (ala
like from a computer) that will pull in or out a
second cap. By balancing a couple of capacitors, I
think a simple design could cover two selectable
portions of the band, 20-30kHz down around 7.04 and up
around 7.285MHz. Or selectable inductors, as you pull
turns or add turns or compress/decompress turns to
obtain the desired result.

Shawn KB1CKT