[Top] [All Lists]

[AMPS] Thank You

To: <>
Subject: [AMPS] Thank You
From: (km1h @
Date: Fri, 13 Mar 1998 09:15:34 EST
On Thu, 12 Mar 1998 15:12:58 -0500 writes:
>Thank you all for the responses regarding Legal Limit Tuners.  I
>received some excellent suggestions.  Everyone agreed to stay away 
>MFJ -- surprise surprise...Some recommended the N4XM unit(dddid you 
>th-th-thousand ??).  Some recommended the old Heathkit roller inductor
>units.  I heard both pros and cons regarding the Nye Viking $800 jobs.
>Lotta oughta be superb...

First you have to decide WHY you need a tuner; then the bands you need a
tuner for.
There is very little reason to use a tuner with many coax fed antennas. I
have loaded everything from A to Z brand amps into coax fed antennas with
up to 4:1 VSWR or so. I use the same dipole on 3.5MHz as I do on 3.8MHz.
I simply changed the value of the fixed loading cap in the amp to
On 160M I run phased verticals and switch patterns cardioid or broadside
and also just selected the fixed Load C in the amp. The idea of outdoor
networks, relays, etc does not appeal to me. 
My HF Yagis are all old homebrew W2PV-4 designs with fairly narrow 2:1
VSWR points...never used a tuner, never had a problem with an amp. 

Remember, a tuner will not make your antenna work any better OR reduce
feedline loss. When I run 100W  I often use the built-in tuner but that
is strictly to keep the xcvr protective circuits happy. 

The Nye and Drake tuners are only L networks, they have very limited
matching range on the lower bands.
The ATR-15 is a very nice unit and is a slightly improved copy of the big
Dentron. It also suffers from insufficient C on 160 and I would not
advise using on 10/12M.

If you MUST have a tuner, pick up a pair of 400-500pf vacuum variables,
turns counters, a large 12-18 position switch, a large ceramic form  from
a fleamarket or a swap newsgroup.....the stuff is out there and at
reasonable prices. Use a length of #8  or #6 bare copper wire or 
refrigerator ice maker tubing for the coil. If you are real lucky you can
find a 15 Amp fixed inductor made by Multronics or others. You can
customize as required and the above parts will handle all the power you
want, even RTTY.
At 1500W + I would not recommend a roller inductor for long term
reliability..unless you get a 15A + edgewound or copper tubing
type....then the stray L &C will limit the upper frequency limit.   

GL   Carl  KM1H

>I didn't hear anything about the Drake MN-4 or the Ameritron ATR-15
>unit.  Does anyone out there have any success / horror stories about
>It may help -- and I should have said this in the first place -- I
>operate 100w up to full continuous power from 160 thru 10 meters.  I
>seeketh DX wheresoever it lurketh.
>73 and gd dx, gentlemen --
>Mitch P. Alexander  KG9DB/4
>FAQ on WWW:     
>Administrative requests:

You don't need to buy Internet access to use free Internet e-mail.
Get completely free e-mail from Juno at
Or call Juno at (800) 654-JUNO [654-5866]

FAQ on WWW:     
Administrative requests:

<Prev in Thread] Current Thread [Next in Thread>