[TenTec] What makes 238 etc. good?

[Rob Atkinson, K5UJ]

I bought a 238A   2 or 3 years ago for $450.  Now they are almost $600.

The costs of decent manufactured Z matching networks are unbelievable to me. 
  The XMatch someone mentioned is over $1000!  Some of the Palstars are over 
$1K too I think.    This all makes the $450 I spent seem down in the MFJ 
range, but for a better product.

One of the common complaints about the 238 is the meter.  I have found the 
wattmeter surprisingly accurate and do not really have a problem with it.  
If you look inside the 238 you will see a somewhat unremarkable roller 
inductor and air variable capacitor.  One of the rotary switches switches in 
fixed disk ceramic caps.  While I wish the components had been a little 
higher quality, I must say I have never had an arc and I have always found 
at most a 1.3:1 match.  There's more to a tuner than the L and C.  You have 
the cabinet, the knobs and reduction drive, rotary switches, circuit cards, 
meter, fixed components, rear panel connectors all getting the cost up.  The 
one thing I wish TT had done with the 238 is put the extra 1000 pF cap for 
160 m. on a toggle switch to make it easier to switch it in and out.  I 
taped mine on a plastic card  and soldered the leads to a lug and alligator 
clip to make it easy to add it or remove it on the back without wearing out 
and breaking the component leads, although there was nothing to stop me from 
drilling a hole and adding a switch.  Maybe someday.

Generally I think the L networks are great.  All I have ever used.  The ARRL 
QST review of tuners a few years ago showed the superiority of the L design 
in my opinion.  I recall the 238 had the widest range and best efficiency of 
all the ones reviewed.  I'm glad Ten Tec makes an L tuner that isn't $1000 
(but it may get there in a few years).

I think the best matching network you can have is the one you designed and 
built yourself because it is (or should be) made exactly to your needs and 
is therefore probably the best bargain for you.

rob / k5uj

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