Topband: what does it take to get on new band 600 meters
Raoul Coetzee
raoulcoetzee at yahoo.com
Sun Nov 5 15:15:05 EST 2017
I have been playing with a few ideas, one was to mix a 6 Mhz Xtal oscilator output with a 6.474 MHz signal from my ft817 (into a small 50 ohm load)the difference, 474 KHz was amplified with tubes (valves for the UK ) and I ended up driving an old 813.Why? because I wanted a job for the tubes that was in the garage.It worked fine, I also used the Ft1000 MP, one vfo set to rx on 474 KhZ and the other to TX on 6.474 MHz using the same valve mixer/amplifier/ driver/PA setup.That project took up space, I had no one to talk to, and ended in the garage with other projects !
The current project is using two TTL decade counter chips (74LS192) to divide a 13.77 MHz signal by 100 , ending with 137.7 KHz, this is amplified by two transistors, and those drive a FET PA.So far getting 47 watts output , nice sine wave after the output filter.Efficiency is a bit poor, I am looking to go class E.
If I use one decade counter, (tap the ouput signal from the first counter) ) and only divide by 10, I could put a 4.74 MHz signal in to it, and get 474 KHz out.Again using the dual VFO's to tx on on 4.74MHz and RX on 474Kc.
Of course, I could use a cheap DDS module and an Ardiuno to generate the signal too, but now I use the rig's switching and keying, no RX/TX antenna relays etc.
I will bottom load the 160m vertical with 5400uH coil and a suitable tap to match.
Maybe this may stimulate some further thoughts and ideas.
Raoul ZS1C
On Thursday, November 2, 2017, 8:40:34 PM GMT+2, Jeff Kincaid <w6jk at sbcglobal.net> wrote:
I've been trying to get Heathkit to produce a dual bander of some sort for the two new bands. Why not start by dropping them a line supporting the idea?
Regards,Jeff W6JK
On Thursday, November 2, 2017 10:35 AM, Kevin Adam <n9iww at LIVE.COM> wrote:
What does it take to get on 600 meters radio antenna transceiver power requirements
N9IWW
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