"Ralph Mowery" wrote in
:


"Jeff" wrote in message
. com...
I would like to see what mods are made to the 221 to do that and
also what kind of antenna system. I have a 221 I am using with a
gasfet preamp in the shack that should be less than 1 db of noise
fugure and about 20 db of gain. The antenna is a klm 22c and 75
feet of 9913 type of coax. I can just see some sun noise with the
antenna aimed at the sun. It sure does not deflect the smeter
several sunits. The antenna is on an azel mount. I am sure the
system is working as I compaired it to an Icom 706 and another
antenna that is mounted on a tower and I am getting about the
differance in signal levels I would expect at the horizon.

The 75 feet of coax is your problem!!! What is the point of a 1dB NF
preamp with all that loss ahead of it? To see the benefit of the low
noise figure the amp must be before all that cable loss!!

73
Jeff
G8HUL

The coax only has a loss of 1 db for the length I am running it. I
doubt that at 2 meters I would see any benift of putting the preamp at
the antenna. It is as easy to get a 1 db or less noise figure at 2
meters as it is to make any preamp and the 221 does need some help on
the receiving side. From the articals I have read the beam width of

Out of the box, the 221 had a noise figure somewhat north of 12db. I've
seen vacuum tube radios that were not much worse.


--
Dave Oldridge+
ICQ 1800667