Jim Reid wrote:
The roller inductor is on a ceramic
> core; MFJ's
> new inductor is air core, and will be higher in Q than were it on ceramic.
> I went to
> the XMatch tuner after melting my earlier MFJ inductor core while on 160;
> that was
> the earlier MFJ design which had a plastic inductor core of some type. I
> did also
> become very frustrated with the poor quality of construction of the MFJ
> the switch shaft would slip, not turn the switch because the internal shaft
> was slipping; the turns counter would slip on the inductor drive shaft, etc.
Every man chooses his own tradeoff points, I guess. After five or six
years of constant maintenance and tinkering with the TenTec 238 I bought
used, not knowing any better, I would probably agree that the XM is a
good choice--if I had the money, which I do not.
TenTec and MFJ each put the lie to "American craftsmanship,"--although
in fairness each targets a wider market than N4XM or Nye-Viking. The
TenTec is a marvel of cost-cutting from a company that basically makes
boxes. The cost-cutting is clever, but not confidence-inspiring:
* couplings made of plastic
* extension shafts of phenolic or fiberglass or some other fiber
* a cheap meter of translucent plastic that serves to diffuse the light
from a 12V bulb that also sits in front of a piece of aluminum angle
stock that serves as a reflector--careful:-the bulb easily melts the
* a rotary inductor with a ceramic core--but with end plates made of PC
board stock and a roller wheel that wobbles on a floating shaft. It
squeaks a lot and is as smooth as---sand in your crotch.
* a sliderule dial-cord assembly whose tensioning elastic was an early
and chronic failure
* coax connectors riveted at two holes of four--badly--necessitating
replacement with screws
* disc ceramic padder caps;
* the obligatory, generally worthless 4:1 balun, smoked early-on when
presented with the ridiculous impedances not infrequently seen with
* a TT case with the cutesy plastic side trim pieces, whose plastic
nipples break off after the second or third removal--not to mention no
RF sealing where those pieces mount.
* cheap knobs
The roller inductor and its cheezy dial finally got me--this weekend I
yanked both and installed an old BC375E roller inductor and counter,
purchased most reasonably at a flea market, years ago. The impulsive
decision to do surgery came after I saw--too late--a Nye-Viking MV5-A
offered on PacketCluster for $350. It went in a microsecond. I needed to
cut a lot of big holes in the 238's inner and outer panels and extend
the spacers and couplings. But it is brass, ceramic and cast metal that
cost us taxpayers a mint decades ago, perhaps when I was still in
diapers. It's not an XM or an MV5-A---but it's sure better than it was!
The circuit? Series L, shunt C, with the C switchable between eingang
and ausgang. That part I like: CONTEST tuning is quick and easy.
"Alternating currents are dangerous. They are fit only for
powering the electric chair."
-- Thomas A. Edison
Editor, "The DXer"
--monthly bulletin of the Northern California DX Club
>From email@example.com (Scott Neader) Wed Jul 31 06:41:06 1996
From: firstname.lastname@example.org (Scott Neader) (Scott Neader)
Subject: Free ham classified ads on the web!
>I don't know if this is appropriate, but I am looking for an Amp. Something
>that runs 160 through 10 meters from 1000 to 1500 watts......
If you're looking to buy or sell equipment, especially stuff used during a
CONTEST, check out this FREE service via the web:
Ham Heaven Classified Ads
73 - Scott KA9FOX
Disclaimer: Trey said it was OK to post this.
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