[Antennas] Mobile Antennas - which shoots best, is strongest?

Fri Jun 16 01:57:43 EDT 2006

Hello Doc - you don't give me a short name in your signature, so I'll use 
this!
Thirty-three foot - the shorter version of the Marine thirty-five foot whip? 
How neat - it would work 40 meters without a tuner.
That sounds like a great install.
Did you bury the ATU? I guess you'd have to put it inside a vented box and 
put a rubber hose to a descrete place so you could fill pressurize it with 
nitrogen and keep the moisture out.
My fallback plan (more visible) was a Hy-Tower and a base mounted SAILOR 
marine ATU-1500 tuner.
You know what I noticed? I had several antennas on my ship, so I used a 35 
Sheakespere whip fed with coax and ran it into my cabin, and I tuned it with 
a small MFJ tuner.
One Christmas, I was near Singapore and I really wanted to get a phone patch 
home - K4HAX ran a 4 element 204BA HYGAIN yagi with a National NCL-2000 amp 
running off of a pole pig - but he said I was S-3.
I really wanted to go talk to my kids. I'd been away from home too long!
So I went into the R/R and turned on the HF transmitter and used the Harris 
ATU to resonate the remotely tuned transmitter whip for 14,320 kHz and then 
took a 20 foot length of RG8/U as a jumper cable and put one end in the ATU 
input and the other, I ran to my stateroom.
Now with my Ten-Tec Triton 2, I was S-7.
Same length of antenna, but this appeared to be the efficiency difference of 
matching the antenna at the base, as opposed to running 30 feet of 
mismatched RG213/U to my stateroom and then using a small MFJ tuner.
Do you think using the vacuum variable in the Harris ATU and matching the 35 
foot marine whip directly at the base could account for all that difference?
Have you experience anything like that?
I liked the system your running (the same as on the ship) but I found the 
bandwidth and matching really touchy below around 2.5 MHz. It was super 
touchy down around 1650 kHz. Some of the guys had a big egg-beater top hat 
so they could use it all the way down to 410 kHz - "in theory" it was 
supposed to be efficient there, but it was several S units down from a 
standard "Twin-T Marconi" or an Inverted-L antenna.
I'm sure Jack Painter, would love to get his finals on that system you have!
73
David Ring, N1EA
=30=
73
David N1EA 