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Hi David and all.
Peter G3LDO has leant me his Decca for a few weeks
and
I have re-modified it for 73KHz.This mod. uses
additional coils which slide into the existing ones so enabling fine adjustment
and are of course easily removable so that the transmitter can be put back to
136 in a few minutes.
On 73KHz I am getting 4A into my aerial (this
requires 950W from the Decca),but it runs very cool.
The vert section of my Ant. is 14.5M high and Eznec
gives me a Rres. of 0.018 on 73Khz. So at 4A I have 288mW Rad.Pwr. Field
strength tests on 136 ( I hav'nt done any on 73 yet) indicate
a
3db loss. Assuming the same on 73 we have 144mW.
However I am a bit confused here after reading Dicks comments on
your
marathon tests,in which he mentions 2.62db gain for
a monopole. If this is correct then the loss due to the environment is 5.62db
not 3db. For the moment I am staying with 144mW which is a little under
half of the power I was radiating earlier in the year on 136.,with
reasonably good conditions I recon it should get across.
I hope the frequency is clear ,John did not seem to
have any problems when he heard me earlier and Jon also recons its
OK.
I will beacon again tonight although things appear
very disturbed at the moment.
I will also be at Windsor on the Saturday and
possibly the Sunday.
73s Laurie.
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