[AMPS] Have Cake & Eat it too

[Gilmer, Mike]

Wow. This is a very different scenario than what I first
pictured/assumed (I know, I know) you were talking about.

You seem to have several problems with your system and you need to
isolate them or you'll go crazy :)

So, unless I've missed something else...

1. I don't believe your 40 meter antenna should be overly affected by
the close proximity of the TH7 - a few points of SWR, maybe.  Having an
SWR of 5:1 or 8:1 says there is something wrong with that system as it
stands.  So either the antenna (balun?)itself has a problem, or the
feedline/switching that feeds it does.  If some of this is shared with
the path to the TH7, then of course the operation of the TH7 will be
affected, too.

2. If your SWR is changing with Power, then your coax is bad (*maybe*
some other piece like a switch or a balun has gone bad - but they tend
to either work or not). CHECK THE COAX FIRST.  You said the 40M antenna
SWR is bad even running low power, however.  If you go WAY down to say 5
Watts, and take the Amp and the switch out of the line, what does the
SWR of the two antennas look like?  Take notes and do a complete check
of the bands.  Try swapping/replacing/removing feedlines/switches, etc.
Assume NOTHING works.

3. The high end of 15M last time I looked was 21.450.  I wouldn't expect
the match to still be good at 21.800.  Check the specs for the antenna -
my guess is that 2:1 BW is about 300KHz or so.

4.

You said:
SWR/Power meter is after the AMP. Station layout is:	

FT-840----->AMP.---->remote ant. switch box---->SWR/Power Meter

Why is the SWR meter AFTER the switch? Where are the antennas?

Should be
(best viewed in fixed width font)

                                      ---Ant 1 (TH7?)
Radio --> AMP --> SWRMeter --> Switch
                                      ---Ant 2 (40M)



73
Mike
n2mg@contesting.com



On Thursday, September 09, 1999 7:11 PM, Jonathan Kaplan
[SMTP:jonk@jskent.com] wrote:
> Barefoot most of  the SWRs are good, 1.5-2.0:1. The exceptions are
3.0:1 in
> the
> high end 15mtr band (ca. 21.800mhz) and 5-8:1 in the 40 mtr band. 
> 


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