EMRFD Message Archive 784

Message Date From Subject
784 2007-05-22 16:16:51 topossibilities Details on MC1496 based SSB Transceiver
I have been asked to provide more details of your 1496 based 75/20M SSB

I have created a folder in the 'Files' section named 'SSB QRP
Transceiver' with the schematic diagrams.

The version shown is for 75M (just need to change the filters and CO
for 20M operation). It was built on a 5" x 7" PCB. The mike pre-amp is
for a hi-Z microphone (used a Shure 444).

Had outstanding audio reportsand worked 88 countries the year I built it.


Lots of parts for sale at:

785 2007-05-22 17:27:32 Kevin Purcell Re: Details on MC1496 based SSB Transceiver
What a neat transceiver design, Ed.

Very simple. Like the Plessey Manpack portable military designs (and
mentioned in EMRFD).

I particularly like the TR switching -- one relay from the PTT to
switch antenna and transmit and receive power lines. Then using the
bias voltages picked up around the filter to switch the crystal
filter with PIN diodes.

Did you make any measurements on it? MDS? DR? NF?

Informal measurements? Was the noise figure lower than the antenna
noise? Much lower?

I see all the 1496 are running at Moto speced 1.25mA. Something to
change to improve performance IMD :-)

795 2007-05-24 12:14:25 topossibilities Re: Details on MC1496 based SSB Transceiver
797 2007-05-25 08:22:49 Kenneth Stringham Re: Details on MC1496 based SSB Transceiver
This is a perfect example of why QRO is not necessary.
This will remain so until we have to deal with
universal deployment of BPL. Then we'll all need QRO
just to make local contacts.

Ken - AE1X

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