[TenTec] Field day antennas

[Jim Brown]

On Wed,4/15/2015 11:32 PM, Don Jones wrote:
> With everything being 50 ohms the performance of the bandpass filters 
> and coaxial stub filters were flawless. 

BS. Everything is 50 ohms ONLY at the fundamental frequency for the 
antenna. At ANY other frequency, everything, both transmitter and 
antenna, is VERY different from 50 ohms resistive.

For the CA QSO Party, we operate CW and SSB on the same bands with K3s 
and 600W power amps, usually KPA500s. We are able to operate on the same 
bands, 20, 15, and 10M with about 200 ft separation with 2-element or 
3-element Yagis that are approximately inline with each other (that is, 
each is at 90 degrees to the other), and about 400 ft separation of 
dipoles on 40M and 80./75 M.  EVERY feedpoint has a SERIOUS common mode 
choke, and, as noted, the radios are K3s. You could not do that with 
lradios or power amps of lesser quality.

At home, under controlled conditions, I can run 1.5 kW with K3s driving 
Ten Tec Titan 425s into 3-el Yagis on the same band about 200 ft apart 
within about 100 kHz if those Yagis are at inline with each other. They 
satisfy that condition aiming about 70 degrees. This is the result of 1) 
VERY clean radios; 2) VERY clean power amps; 3) VERY bulletproof 
receivers; 4) antenna directivity; serious common mode chokes on each 
antenna at the feedpoint; and 5) high quality coax (in this case, 7/8 
hard line or 1/2-in CATV hard line) and high quality patch cables inside 
the shack. The Titan 425s were designed around 1978, but they got it right.

At that CQP site, every cable is high quality RG8 or RG11, and every 
connector is hand soldered.

73, Jim K9YC