I've had experience similar to that described below with their products, of
which I have a number, some active, some passive. I've learned the following:
(a) don't believe their CCS and max ratings; IMHO they've been somewhat
optimistic.
(b) the same sentiments re QC that are expressed below. I open and
examine them the same way I would examine an early HeathKit or DynaKit that I
was resurrecting, one which I made before I had much experience in assembly and
soldering,.
Along these lines: I just got an MFJ 998RT, the 1.5 KW, 1.8 - 30.0 MHz, remote
antenna tuner. I found one of the bolts that is supposed to hold the cover to
its base with its head stripped off. I also found that they used wire at least
two gauges smaller than I would have used to wind the coils.
QUESTION: I plan to use the 998RT in my attic right now, not outside, and am
thinking of running it with its cover off so that it runs cooler. Their
instructions say not to do this, although this seems to relate to safety issues
(high RF voltages) rather than function. The cover is made of plastic, not
metal, and therefore not a shield against harmonics radiating. Does anyone
else have any experience with running this or any other of their remote tuners
without covers (indoors, obviously)? Comments or suggestions?
I do like their value, and as below, will probably continue to buy their stuff,
with the cautions above. I also particularly like their not cancelling the
warranty if you open the device, since I always do.
Ref SWR meters: I like the "computing" type of SWR meter, like first described
in QST by Fayman W0GI about 30 years ago. This displays SWR directly,
computing it from forward and reflected power and not requiring one to either
read some obscure needle intersection, or switch back and forth between forward
and reflected power. I still have one of his design I made back then.
Grebencamper has described an updated version (in the ARRL Antenna Book -
haven't tried it, but the circuit is similar), and Autek Research in FL makes
and sells them. I have one of these also and like it. These are VERY handy
instruments for Field Day, or for people who have to squeeze their antennae
into small attics.
Tnx es 73,
Gene May
WB8WKU
RECENT RELATED POSTINGS:
> Date: Mon, 10 Sep 2012 04:00:26 -0400
> From: k8ri@rogerhalstead.com
> To: amps@contesting.com
> Subject: Re: [Amps] SS Amp questions
>
> On 9/10/2012 12:53 AM, Jerry Kaidor wrote:
*** My impression of MFJ is that they do have some pretty decent engineering
in their stuff, but their quality control is strictly to meet
a price.
>
They do make some handy equipment that works fairly well, they make some to a
price and stretch the power out beyond reliability limits, but you only need to
look at the QC on the same items built under their control and without to see
what building to a price can do.
I still use their products, but pay attention to what I get.
>
> 73
>
> Roger (K8RI)
open the> >
> > - Jerry Kaidor, KF6VB
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