[TenTec] 229B tuner: Slight upward creep of SWR

[Peter Klein]

I've just noticed something interesting about my Ten Tec 229B tuner.  It 
happens on 80m-30m, where the center switch is in positions Lo2 - Lo5 
and various fixed capacitors are switched into the circuit.

I use non-resonant antennas fed with ladder line.  I normally tune the 
tuner with a noise bridge or at 10 watts.  Then, when I operate at 100 
watts, I notice a slight upward creep of SWR over a few seconds after 
key-down.  Then the SWR backs down a little and remains stable while I'm 
transmitting. The creep is very slight, from 1:1 up to maybe 1.2 or 
1.3:1 on my IC-7300's SWR meter.  My guess is that this is the same 
issue some people report with the Ten Tec tuners on 160m.  On low 
impedance loads that require the extra fixed capacitors to switch in, 
those capacitors warm up slightly and change value as we transmit.

I never noticed this before.  But I just picked up a used Daiwa CN-101L 
cross-needle SWR meter, because the tuner's switched meter and the 
IC-7300's multiple displays make monitoring SWR inconvenient.  The 
Daiwa's "reflected" readings are a bit overly sensitive. On that meter, 
I could clearly see the creep happening. Sure enough, when I looked on 
my IC-7300's SWR meter, it was happening there, too. The Ten Tec tuner's 
meter barely shows it, if at all.

My guess is that everything is fine.  The SWR creep is too small to 
endanger my finals, and I can always touch up the tuning.  I just want 
to be sure that the SWR creep doesn't indicate that the fixed capacitors 
in the tuner are failing. Can someone give me a reality check?

Thanks and 73,
--Peter, KD7MW