--- Bruce Robertson broberts@mta.ca wrote:

Bob:

An important factor you don't mention is the coax to your antennas. If you are not using preamps, the losses of the cables decrease the noise figure of your reception by the same ratio, and this can add up very quickly to an unworkable situation.

Hi Bruce,

Sorry, about that. I'm using wireman's #106 which is a low-loss foam RG-8 type with both braid and foil shielding. Also, there's only about 35 feet of it, so the loss should be be very low.

I think most of us also believe from experience that mast-mounted, low noise preamps (from ARR or SSB USA) do far more for a station than polarity switching. These are not inexpensive additions, but, especially on 70cm, they are indispensable.

Here's what's happening. From about 20 degrees up to about 30 or so, reception is iffy. After that, I sometimes have full quieting and sometimes nothing. I suppose I need to do a real study of it on one satellite, but it just seems that it should be a polarization issue. I do have a spare coax going up there, so I guess I could just make a LHCP version to be sure. Getting it out on the roof means that I have to make a much more robust version. I was hoping to put that off until I was completely sure that I've got a configuration that works properly. It's much easier for me to just move the antennas to the back yard when mowing season is over (I'm disabled). Fortunately, I have a semi-finished attic with easy access.

Another thing I've been thinking of is that once I'm comfortable with messing around with relays etc on 70cm I might be able to use a DEM preamp with my own switcher. Thus my question on the relay.

Bob - AE6RV