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

Re: To: k5oe@aol.com



If you are using a helical feed designed for a shallower dish, it will
underilluminate your deep dish resulting in low gain. Make the helix
shorter.

I am using a 3-turn 1-1/2" D helix with 3/4" turns spacing for a 0.3 F/D
dish. Matching is accomplished by flattening one end of the 3/16" D copper
tubing over the last 1/4 turn and soldering to an N-connector. The last 1/4
turn is spaced 3/32" above the ground plane with teflon sheets to form a
50-ohm microstrip line. The helix is contained in a 4" x 4" x 2-1/4" box
with one end open.

73,

John
KD6OZH

----- Original Message -----
From: <kgschaffrath@beckman.com>
Cc: <amsat-bb@AMSAT.Org>
Sent: Tuesday, 29 May 2001 15:30 UTC
Subject: [amsat-bb] To: k5oe@aol.com


> Hi Jerry,
> Im also playing with canned-helix feeds on dishes. so far i have not been
> able to improve
> over the stock dipole on the 3733 , this may be to my dish being f/d .24
> very deep.
> anyway,  i copied the beacon from about MA50 -60 this morning with very
> good signals.
> about S4 to S5.  so it was there.
>
> Keith N6ORS
>
>
>
>
> ----
> Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
>

----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home