I spent most of today (Sunday) removing the TenTec supplied auto-tuner
and putting the LDG in its place. ( a couple of times actually - not
fun!) For now, I'm keeping the TenTec model. Here's why...
Basically, I like the way the TenTec one works now. When the TT one
tunes and you don't like that it came up with 1.8 or 1.4:1 or whatever,
you can re-tune with two pushes - one to turn off the tuner and then
again to bring it back on and do a "re-tune". The TT tuner seems to
"start" at the last tune setting and it usually improves on the match.
The LDG model does not allow this. Whatever you get from the tune cycle
is what you get - no refinements- if you invoke another tune it either
will select a memory one (like the last one it just did) or if you force
it to fully re-tune it starts from scratch and then stops where it did
before.
Another reason for keeping the TT model for now is sort of alluded to in
the last paragraph. It doesn't match as well as the TT version. Using
the same antenna for a run through all the bands, the TT would give an
average of 1.1:1 (on the first tune) while the LDG model only got to
1.4:1 on 3 bands and most bands were 1.8:1 or as much as 2.0:1 on 10
meters. I use a 500 foot loop at 50 feet fed with 450 window line. The
TT model has no trouble with it. I'm pretty sure the LDG match would
improve if it would allow a "refine" second tune, starting from the last
known match. But it didn't "first tune" as well as the TT model. I
thought my other LDG tuners did better on the first stab at a match, but
its been a while since I used them.
I'm an LDG fan as I have a few of their tuners for other situations.
This one missed the mark for me. Perhaps they will read this and look
at modifying the firmware to allow the "refine" tune. 200 memories
aren't useful if they are all at 1.8:1 or so.
In looking closer at the TT model, I noticed a lot more circuitry -
perhaps mostly unused. Not sure. BUT, it looks like it is capable of
receiving band information via a communication port on the board that is
presently not hooked up. Wouldn't it be great if TT was able to someday
have the tuner remember tune settings per band so that when you change
bands with the tuner enabled, it would automatically change the tuner
settings. (oh yeah..., like my $800 K2!)
One the topic of hardware, the LDG model has 7 inductors and the TT
model has eight. The TT model has a lot more (tuning) capacitors but I
suspect they are paralleled to make the values they need. Not sure but I
think they both have at least eight actual tuning capacitor values. I'm
looking for the schematic of the TT tuner if anyone knows where to find it.
Installation note: If you already have the TT tuner installed, the LDG
directions ignore this. I found myself wishing they had allowed for
guys like me who already have wires run throughout the radio and only
need to change the board. Some female jacks on their tuner board (just
like the TT one!) would have been really handy. As it comes from LDG,
they solder the In and Out cables to the board and force you to replace
the TT ones. A real pain and waste of effort.
And while I'm whining about the install - some kind of mating connector
for the control wires coming from the front panel would be nice too. I
fabricated a way to mate them so I wouldn't have to dig into the front
panel. Bottom line: Looks like the LDG tuner is not ready for prime
time but not far from being all it is supposed to be. I'm keeping the
TT model installed for now.
(Epilog: I had posted this on the Orion reflector and there enusued a
"whats wrong with 1.8:1?" kind of exchange. Whats wrong with it is I'm
used to seeing (for bad or for worse) 1.0:1's with the TenTec tuner. I
didn't expect to go backwards with the new tuner. I'm investigating
some technical aspects to determine why the matches aren't as good.
Until then its on the bench and not in the radio.)
73,
Randy
K4QO
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