EMRFD Message Archive 1519

Message Date From Subject
1519 2008-03-25 19:36:56 Roger Hayward test message
Just posting a test message. The group has been unusually quiet in
the past week. Maybe it is the change in weather.

I hope everyone is having fun experimenting. 73, Roger
1520 2008-03-26 14:23:23 cwfingertalker Re: test message
Hello Roger,

Lots of solder smoke over here. Finishing up the two HYCAS boards. Also
homebrewed two 9 mhz crystal filters. I have been spending a lot of time re-reading
various ham books and articles about VFO's and mixers. Always have something new
to learn.


Bill N7EU

Sam's Valley Oregon.
1522 2008-03-27 07:17:21 Allison Parent Re: test message
1523 2008-03-27 07:52:55 cwfingertalker Re: test message
> One of the hardest things is deciding what the next bands the SSB
> transceiver will cover..


I would suggest 6 meters. Maybe a revival of the Heathkit 6 meter lunchbox. Make it
SSB with 5 watts. Enough power to drive a brick amplifier. That would be a great
group project too.

Bill N7EU
1524 2008-03-28 05:06:01 Allison Parent Re: test message
1527 2008-03-28 09:50:31 cwfingertalker Re: test message
> As far as a group radio after building more than a few I can say
> minimalist radios on six don't really make it. You need a sensitive
> RX for the weak signal times, selectivity for the band openings and
> AGC is a must to avoid frying your ears. Generally that makes the
> radio more complex. It can be done but things like stable VFO
> or a fairly quiet PLL for tuning add a lot to the total design.
> Allison


Hmmmm. A stable VFO (maybe better a VXO centered on the SSB calling frequency),
use the HYCAS IF amp, INRAD 2.4 khz wide 9.0 mhz IF crystal filter and a sensitive RF
amp lineup. If you use the VXO make it a 6.866 mhz oscillator with a x 6 multiplier
to 41.2 mhz (9mhz IF down from 50.2mhz). Sounds pretty minimalist to me.

Bill N7EU
1537 2008-03-30 14:56:57 Harold Smith Re: test message
Another possible combination for 6, from standard microprocessor crystals:
VXO at 20.48 MHz, tripled to 61.5, with an IF at 11.228 MHz. The sideband
inversion puts the BFO on the right side of the filter for USB as well.

de KE6TI, Harold

1538 2008-03-31 04:46:42 Allison Parent Re: test message
1539 2008-03-31 05:06:43 Allison Parent Re: test message
1541 2008-04-01 21:23:19 Harold Smith Re: test message
Actually (20.48 * 3) - 11.228 is 50.212 MHz, and a two crystal VXO will
easily pull far enough to get down to 50.1. I know, because I'm building
such a radio now, though it's not particularly minimalist. I used the VXO
approach as an easier way to get stability at the higher frequency needed.


On Mon, Mar 31, 2008 at 8:06 AM, Allis
1542 2008-04-02 06:20:57 Allison Parent Re: test message