[AMPS] FAILURE OF PARASITIC RESISTORS IN AL-811X AMPLIFIER

Thu, 2 Mar 2000 10:35:23 -0500

>> I have had the great misfortune to receive (free) two mfj "3kw" antenna
>> tuners.  Pure junk! - mediocre design and very poor implementation.

>A tuner sold by Ameritron (ATR-20) using the same inductor is 
>rated at 750 watts CW, but there are electrical differences. The 
>Ameritron tuner includes a peak reading meter that really reads 
>peaks, and has higher capacitance variables.

>> I had an mfj antenna switch - also junk - it is now contaminating a
>> landfill somewhere.  

>The four position indoor MFJ antenna switches had a dimension 
>error in the casting for the housing that prevented the contacts from 
>seating properly. Some worked, and some didn't.

>73, Tom W8JI
>w8ji@contesting.com

I don't remember the nomenclature, but the antenna switch was their qro
6-position switch with receptacles for pl-259 connectors.  The fundamental
problem was that the connectors themselves were of outrageously poor
construction.  The center contact was made from very thin tin sheet that
would become permanently bent once a PL-259 connector was inserted.  After
that, they would only make intermittent contact.  The quality of the switch,
connectors, wiring and soldering was horrid!  I believe they are still
selling this exact specimen, sans improvement.

About the only thing ok about this switch was the medium gauge aluminum box
it was built in - at least it can be recycled and turned into beer cans!

73 Tom,

de Don, ki6sz

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