From: "jannsen" <0482183881-0001@t-online.de>
To: rsgb_lf_group@blacksheep.org
References: <5.0.2.1.2.20011124174547.00a15a90@mail.pncl.co.uk> <002d01c1751e$f89d1f80$28b51bca@rvernall>
Subject: Re: LF: Re: Earth losses
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Date: Sun, 25 Nov 2001 17:44:05 +0100
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Vernall schrieb:
...........................
> Even though the transmitter is optimised for 50 ohm loading
> (low pass filter and coupling designed for 50 ohm interconnection), that
> does not mean it is 50 ohms looking back into the transmitter.  

................
> I believe the
> explanation is in the differing resistances (or impedances with differing R
> component) of the transmitter output and receiver input.
>

Hi Bob,

guess we have to go one step further: looking back from the antenna into the 
loadingcoil. 

I f.e. have to adjust the variometer of the loadingcoil (searching maximum of 
rx-voltage or antamp peak with an hitzdraht ampmeter)
1. if switching from rx to tx 10W output
and newly
2. if switching from rx to tx 100W output (test)
and
3. if switching from rx to tx 500W output (test).

the adjust degrees at the variometer differ vy little switching the tx from 10W 
to 100W to 500W. the bridge shows no difference, but the hitzdraht ampmeter 
(peak) does.

from rx (FT1000) to tx  10W (Z 50ohm) it is abt 10ohm (!) up.

regards
Uwe/dj8wx