Tetrode QRO

W8JITom at aol.com W8JITom at aol.com
Sun Apr 7 21:26:39 EDT 1996

In a message dated 96-04-07 01:56:00 EDT, you write:

>Hi Garry, we seem to be tuned at the same wavelength (no input coils
>I modified my SB-220 by grounding grids directly as one of the initial
>designers admited it was mistake to introduce RF feedback without the
>of the phase relationship over the 80-10m. 

That initial mistake was the result of following the data in the Super
Cathode Driven circuit articles.

What you say is true Mario.

Just like you did Mario, if you remove the silver mica caps and chokes and
ground the grids directly in the SB220;  IMD performance, stability, and gain
flatness improves.

73, Tom

>From Jim or Tim Spaulding <tjs at dfw.net>  Mon Apr  8 09:27:21 1996
From: Jim or Tim Spaulding <tjs at dfw.net> (Jim or Tim Spaulding)
Date: Mon,  8 Apr 96 01:27:21 PDT
Subject: antenna heights
Message-ID: <Chameleon.4.01.3B.960408012917.tjs at hamradio.dfw.net>

I agree fully, using the same thing for 12 years, except I shunt feed
the tower and use a sloper on 80/75.  At my new QTH I intend to replace
the sloper with a wire 4 square, no other changes necessary.  Antennas
are a TH6 and KLM 2 El 40 on a Hygain HG70
73 de Jim W0UO/5

>Here is the best single tower/simple tower antenna setup that can be 
>HyGain or other 70ft crank up (second choice, 70 ft guyed).
>TH-7 just above the tower top.
>40-2CD 12 feet (NOT 10ft) above TH-7.
>75m and 160m 45degree angle slopers off the point just under TH-7.
>If you compete against others who do not pad their logs, and if you are a 
>great operator, you will win from time to time against any other antenna 
>set-up in comparable geographic location.
>Been there, done that, made up some shirts and wore them.
>73, K4VUD

More information about the CQ-Contest mailing list