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When I am not running my KX-1, I use an Orion and a Titan III amp. Before my divorce, I lived on 5 acres with all kinds of neat antennas.

Now I am in a cool little house in the woods, and use a SteppIR BigIR and will augment that with a Force-12 Falcon J-5.

Even though these antennas are resonant on the band they are switched to - I was wondering if it might be a good idea to always use a tuner inline anyway - just in case something fails between the antenna and the amp?

I went with these antennas to avoid the use of a tuner, but then started thinking . . . . if anything were to go - I would rather have the tuner go than the amp or rig.

Just one of those wacky thoughts that crossed my mind on a long bike ride.

73,

Rich

[AA4PB]

If the antennas have a reasonable SWR (under 2:1 with most rigs) over the part of the band you want to use then the tuner won't do anything for you. If something suddenly changes in the antenna (a short or open) the tuner won't protect the rig. The tuner won't be tuned for a match under those conditions and will simply reflect a poor SWR back to the amp.

If you have an antenna fixed tuned for the center of a band then a tuner can be used to bring down the SWR when operating at the band edges. With a tunable antenna like the STEPPIR you just tune the antenna and there is no use for the tuner.

[K6HYA]

Hi Rich,
I'd think that whatever you put in the rf feedline to your antenna will add a little loss.  There's each SO-239 to PL-259 times two per cable, there's the impedance in the caps and the inductor.  These parts can only detune your system.  If you have an antenna that's really resonant at the operating frequency, you'll have no SWR or impedance matching problems.  I'd pull the tuner and keep the unneeded parts out of the circuit.
I'm glad you're situated in your new place.
73,
iggy K6HYA - still waiting to put up the tower and the rest.

Thanks for your thoughts - it makes sense that all the tuner would do is add unecessary loss. I guess what I really need is just a good quality SWR / wattmeter that also lets me switch one antenna or the other inline to the amp. My Orion has two antenna "ports", but the Titan III only has one. Plus, I noticed that the SWR meter built into the Orion always seems high (I borrowed a friends Palstar meter which I believe is pretty accurate). But the difference wasn't very large - and was consistent across all bands. For example, the Orion says 1.4:1 on 40M, and the Palstar - measured at input to the amp says 1.2:1.

[K6HYA]

In one of these forums I read about a concern of having so many different items between the tranceiver and the antenna.  There are the low-pass filters, SWR meters, antenna selector switches, baluns, tuners, etc.  Each item has a coax and connectors that will reflect a small amount of RF meant for the antenna.  Each connection can loosen and change impedance.  The old article showed that all this convenience contributed to the loss of a large fraction of the original signal.  It won't matter a whole lot if you have the extra power in the amp.  But, it will contribute to RFI and you might get to meet the neighbors without the BBQ turned on.  Do you need to keep re-checking these parameters with the SteppIr?
73,
iggy K6HYA

[K6HYA]

In one of these forums I read about a concern of having so many different items between the tranceiver and the antenna.  There are the low-pass filters, SWR meters, antenna selector switches, baluns, tuners, etc.  Each item has a coax and connectors that will reflect a small amount of RF meant for the antenna.  Each connection can loosen and change impedance.  The old article showed that all this convenience contributed to the loss of a large fraction of the original signal.  It won't matter a whole lot if you have the extra power in the amp.  But, it will contribute to RFI and you might get to meet the neighbors without the BBQ turned on.  Do you need to keep re-checking these parameters with the SteppIr?
73,
iggy K6HYA

SteppIR says that their steppir motors are very precise, but my brother, who is a mechanical engineer told me to use the calibrate function every now and then - just to make sure.

I have been using mine for about 2 months now, and haven't found any deviation in measured SWR - using the Orion's built in SWR (LCD) metering function.

So, at least for the last 2 months, the BigIR's Steppir motor seems very accurate. It would be very easy to replace the BigIR's motor if it ever did die - since it is 6" above ground. I did avoid the SteppIR yagi when I had 5 acres and a tower - mainly because of the weight and wind load on my Force-12 LPT-1252 tower (which couldn't handle that kind of load).

And I did go with the BigIR to eliminate unecessary devices inline. And I do agree - my SWR is certainly "low enough". With 64 radials, I have been working EU and AF at night, and AS in the morning - so it certainly seems to be at least as efficient as when I had an MA8040V with 64 radials at the old QTH.

Hmmm - I should look up a forum regarding the SteppIR antennas - it would be interesting to see what people think of their antennas and the motors.

73,

Rich

[WB6BYU]

Personally I wouldn't run the signal through the tuner if
you don't need to - it is one more thing to have to adjust
when you change bands, and one additional potential point
of failure.

I sometimes leave one of my tuners connected in the BYPASS
position so I can switch it in just when I need it.  This
is particularly handy, for example, when I need it for just
one band (usually 160m, where my built-in autotuner won't
work).  The additional loss in the connectors is insignificant
(presuming the tuner is well built) but the bother of having
to adjust it is the main thing.

It won't add any protection for your amps, though.