[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: QFH modification

Dear Mak,

you are talking about the "thin" diameter UT-141 hard line ?
(BTW, that one is easily available by mail order here in Germany)

Then certainly you mean the construction of a UHF QFH model, right ?

In the case of the UHF antenna it will be very difficult to find
such a thin hollow copper tube (most easily available hollow tubes 
from DIY stores start at about 6-8mm outer diameter and thats too
large for the UHF QFH model, since the outer diameter of the
conductor is one important construction detail of this antenna type)

For VHF this method should be OK (as Dave suggested) and is widely used
in the 137 MHz NOAA satellite QFH variants you can find on internet since
the required outer diameters of the four loop elements are much thicker.

Please wait until I have my website ready. I just finished to build my
new QFH yesterday (based on the design of Art, with Bazooka balun, AKA
sleeve balun). Now I need to make the whole QFH weatherproof and I need
to build a new preamp for it and mount it on the roof. It will certinaly
take some more weeks for getting the first impressions "on air".

73 de Oscar, dj0my
Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org