[Hi-zreceivingarraydiscussions] BC IMD

[Lee STRAHAN]

Hi Paul and group,
   It is time I addressed this here on the reflector.
     First it is imperative that the supply voltage at the Hi-Z amps be up around 13 volts or maybe 13.5. This gives the best operating point for the best IMD specs. Also, the new V2 amps draw a bit more current than the older amps so you may want to check that voltage first.
    Secondly I do make some filters for the Hi-Z amps that have a notch in the BC band and usually solves any BCI problems.
I will send this as 2 messages because the reflector is limited in message space.
Lee  K7TJR

Lee,

N4CC and I installed the new Hi-Z preamps on our 160m 8-cicle array.
Balance is better than with the old preamps and while listening last night, F/B was excellent with no signs of skewing.  However, starting at 6:15am this morning, I heard significant broadcast band IMD every 10 kHz on 160m.
We have a Hi-Z HPF between the controller and Hi-Z final preamp.