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Re: [TowerTalk] RG-149: 50 ohm/70 ohm - does it matter?

To: <towertalk@contesting.com>
Subject: Re: [TowerTalk] RG-149: 50 ohm/70 ohm - does it matter?
From: "Dan Schaaf" <dan-schaaf@att.net>
Date: Sat, 14 Dec 2013 13:23:32 -0500
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Tom, the tuner does not fool me. I know exactly what it does. It presents a 50 ohm impedance to my transmitter.

My antennas are resonant at one frequency per band, and of course deviate from resonance either +/- from that point. So, to get max usefulness across the band(s) I use the tuner. In my humble opinion, the least amount of reflected power getting back into my transmitter, the better for longevity of the transistors.



Best Regards
Dan Schaaf
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K3ZXL www.k3zxl.com
60 Meters www.60metersonline.net
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Cape Cod Instruments www.gnm-inc.com
Tel: 941-766-0706
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-----Original Message----- From: Tom Osborne
Sent: Saturday, December 14, 2013 12:10 PM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] RG-149: 50 ohm/70 ohm - does it matter?

I think a tuner only fools people to think things are working right
(unless you use a Matchbox type tuner and twinlead).

If I have a RG-8X feeder, and I operate a 10 meter CW antenna at 28.900,
the amp may be happy and putting out it's power, but most will be
getting lost on the way to the antenna.

Yes, it will work, but not efficiently.  73
Tom W7WHY





Jim

I have an MFJ-998 Autotuner connected to the amp. Every time I change
frequency I mouse click on the TUNE button on the screen, generate a
carrier and the tuner does it's thing.

So, do I have distortion? Not sure, but the tuner does present a good
match to the amp. I do ask on the air about my signal, SSB, CW and RTTY
and always get good reports. Short of having a scope connected to the
coax, I assume that all is OK. Gone are the days of the Yaesu Scopes for
testing transmitter/amp output. I used to have one in line but never
seeing anything obvious on my signal, I finally got rid of it.
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