I believe all the Murch 2000 family use roller inductors.
The B model added 160, a bypass switch and a directional coupler but the
schematic does not list any values. The A model covered 80-10M with 200pf
caps and a 18uH rotary inductor.
Since the cabinets were the same I dont see using higher capacity caps at
the A spacings if they were changed at all.
Carl
KM1H
Carl
KM1H
----- Original Message -----
From: "Richard Solomon" <dickw1ksz@gmail.com>
To: <amps@contesting.com>
Sent: Sunday, February 02, 2014 4:56 PM
Subject: Re: [Amps] Recommended Tuner for Clipperton L
One of the often overlooked Tuners are the Murch UT-1000 and UT-2000.
They have not been made in many years and sell for much less than their
more modern (and expensive) counterparts.
The UT-2000B will cover 160 - 10 and will load up the proverbial
bedspring.
They show up over on the "evil empire" from time to time.
73, Dick, W1KSZ
On Sun, Feb 2, 2014 at 2:37 PM, Roger (K8RI) <k8ri@rogerhalstead.com>
wrote:
On 2/2/2014 2:11 PM, qrv@kd4e.com wrote:
Weird amps list error the first try - trying again ...
Roger,
Would you please explain "hiss"?
iss as in hi voltage arc. Sounds just like a cat or snake.
What, precisely, is happening to create that sound?
If the antenna in highly reactive (inductive) and the SWR is high the
voltage goes high.
Neither the MFJs or Dentrons had a high enough voltage rating for much
over what I'd get when the 160 antenna was resonant near the DX window
and
I'd go to the top of the band.
Moving the resonant point to the middle, or upper end of the band would
eliminate the arcing at 1 KW, but then I had concerns about the small
wire
on the rotary inductor when operating at the bottom end of the band.
They really needed a higher voltage rating on a larger cap and a larger
size wire on the rotary inductor for current on low impedances.
73
Roger (K8RI)
There are so few parts involved it seems that there's
either too small inductance (or perhaps the gauge of the coil
wire is undersized), too little capacitance (or perhaps aging
doorknob capacitors), or a tiny arc across an under-rated switch?
Could it be that a small tweak to one part of the mix of
parts could compensate for the weakness elsewhere e.g. adding
capacitance balances the added stress at 160m such that the
marginal coil or switch is not pressed to the limit?
Trying to understand the "why" behind the symptoms ...
Thanks!
David
I've had no problems with the half sloper, center fed droopy dipole
on 160, or the Fan Dipole on 75. The Dentrons and MFJ 989 series
would all "hiss" at me on 160 near the top end of the band at much
over 1 KW out.
73,
Roger (K8RI)
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