The SWR antenna current is an interesting effect there are several things
this could be ,.It could be that at the highest current you are providing
the right reactive load to move the PA towards Class E or even away from it.
This mode does not give best efficiency at the highest output current and
must be tuned to the "right" power level and not for max smoke.
You need to look at the DC power at each condition.....you may find you are
runing 50 % more DC power for a little more antenna current.
Sorry I was out today so not listening to your tests.
73 Alan G3NYK
----- Original Message -----
From: Dick <[email protected]>
To: <[email protected]>
Sent: 15 August 2006 16:12
Subject: LF: PA4VHF tests finished for now
When tuning the variometer I could see how the SWR changed, however with
lowest SWR I didn't have the highest antenna current.
There is a little difference between these 2.
When tuning for max antennacurrent, the swr is not at it's lowest level, but
a bit up, but below 1:1,5
I couldn'r run more power, because protection circuit of TX came in.
Had to reduce voltage to 42V in order to keep the TX running.
I have to change the output transformer I'm afraid.
It does work perfect into a 50Ohm dummyload, but when connected to the
antenna, things are different.
Also burnt my fingers on a little metalswitch.......oeffffffff..there was
strong RF present on TX case.
TX was close , within 3m of antenna.......can't advise that, hi.
Later changed that to 6m, and no more RF-on case, hi.
73
Dick, PA4VHF
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