Help w/Amp 80m Anomaly?

W8JITom at W8JITom at
Wed Jan 15 23:17:03 EST 1997

In a message dated 97-01-15 09:59:58 EST, you write:

>I purchased a used MB-V-A from a sale of surplus equipment from
>a previous Greenpeace operation in the Antartic.  The unit had
>burned sections of tinned copper braid between the terminals
>and the components.  It had been in service with an Alpha 88, into
>a variety of non-resonant wire antennas.
>After replacing the braid, the unit has operated reliably
>at the 400w level for several years.

Braiding has much higher RF resistance that the same area smooth conductor.

Measurements I made several years ago at 30 MHz on a new chunk of 1/2 inch
wide copper braid indicated it had an RF resistance about equal to a number
12 wire.

The resistance varies with the depth of the weave, cleanliness of the braid,
and the mechanical pressure of the wire to wire connections in the braid.

NASA prohibits use of braiding for lightning protection and RF grounds unless
the connection absolutely has to be flexed. 

73 Tom

>From n4bp at (Bob Patten)  Thu Jan 16 07:34:57 1997
From: n4bp at (Bob Patten) (Bob Patten)
Date: Thu, 16 Jan 1997 02:34:57 -0500 (EST)
Subject: FSFD (50 States) Update for Jan 15 (fwd)
Message-ID: <Pine.SOL.3.91.970116023357.11766D-100000 at hyper>

---------- Forwarded message ----------
Date: Wed, 15 Jan 1997 22:27:07 -0500
From: Jim Hydzik <congress at>
To: Low Power Amateur Radio Discussion <qrp-l at Lehigh.EDU>
Subject: FSFD (50 States) Update for Jan 15

Hello ALL,      (QRP activity info at

The 50 States In 50 Days (FSFD) activity started Jan 01 and runs through
Feb. 20.  Below is a the schedule of States for the next few days.  We will
attempt to provide digested schedules of states/times/bands/freqs. to help
reduce message traffic to the reflector.  Typically, only 1 message per day.
                                          ALL TIMES UTC
Jan. 15  Wednesday IOWA KD0CA, Jerry 1230-1345      UTC   3.559
                                     0100-0300 Thur-UTC   7.042
                                     0300-0330   "  UTC   7.039

Jan. 16  Thursday WISCONSIN  (substituted in place of Kansas-later)
                       WA9PWP, Paul  2300-0000      UTC   10.115
                                     0100-0300  FRI>UTC    7.037
                                     0300-0400  FRI>UTC    3.700
Jan. 17  Friday  KENTUCKY KC4O, Roy  1400-1420  FRI-UTC    7.042
                                     1430-1445             7.118
  E-mail Roy for any spcl.           1500-1520            14.059
   times or freqs.                   1700-1720            10.115
                                     1800-1815            18.078
                                     1830-1900            10.115
                                     2100-2120             7.042
                                     2130-2200             7.118
                                     0000-0100   SAT-UTC   7.042
                                     0100-0120    "   "    7.118
                                     0130-0200    "   "    3.710
                                     0215-0400    "   "    7.042


Jan. 18  Saturday  LOUISIANA #2,  K5RV, Brian    TBA  (ends at 6 PM)

   | Look at MI-QRP Contest this weekend; Info-Jan QST |
   | Start 0700 UTC 1/18/97    End  2359 1/19          |

Jan. 19  Sunday   MAINE, WA5CVM, Joel, after MI-QRP Contest   TBA  


Most every sign-up came with a note saying they would go longer if busy.
Frequencies are +/- QRM & typ. may reach as far as 3-4 KHz from posted freq.

CALLING CQ:  A suggestion.  If we call CQ WAS  or  WAS QRP de K6....  etc,
we give those not on QRP-L an indication of what we're doing.  FSFD type
calling might be too cryptic for all but ourselves.  However 'FS' is fine
when busy.  Exchange RST, State/Province/Country, and Name.  Power level is
nice to know.

ALASKA & HAWAII:  Jim-AL7FS is back from Hawaii and will activate ALASKA as
soon as KL7Y's 40M beam repairs are complete.  Watch for Jim's postings.
Thanks to him for the HI effort.
KB0ROL will also be in HAWAII between Jan. 17-25 and will post his time/freq
info to the group when ready.  Don't miss this double QRP HI shot.

If you want to sign-up for an upcoming State, e-mail band/freq/time directly to:
                         congress at
Thanks for all the responses/encouragement and suggestions.  Lets have a blast!

Jim  K3QIO  Wilmington, Delaware  

>From morel.grunberg at (Morel Grunberg)  Thu Jan 16 12:36:50 1997
From: morel.grunberg at (Morel Grunberg) (Morel Grunberg)
Date: Thu, 16 Jan 1997 14:36:50 +0200
Subject: Hy-Gain TH-11DX beam : opinions summary
Message-ID: <c=US%a=_%p=TELRAD%l=MISMAIL-970116123650Z-102 at mismail.MIS.ELEX.CO.IL>

  Two weeks ago I sent a request on few relevant reflectors asking for
opinions on Hy-Gain TH-11DX beam. Till now I received 84 answers from
United States
( 74 ), Europe ( 4 ) Asia ( 4 ) and Africa (2).
   I was quite surprised about the very favorable opinions from the
people who taked the time to answer. Actually, 82 were very satisfied
with the antenna and
warmly recommended to buy one. 
   This is a brief summary of the answers:

   This beam was described like a real winner and a very good and
effective solution for those who need a 5-bands beam with reasonable
gain, F/B and
good SWR. Here are the opinions:
* 72 declared their satisfaction on general radiation performance and
  results while only four are not so happy with the front to back ratio.

* 55 were very satisfied by the good SWR over the 5 bands and only four
  reported SWR problems as result of bad assembly work, improper
  and insufficient tower height.

* 60 declared their satisfaction over the ruggedness and mechanical
construction quality.

* 19 favorably compare the TH-11DX electrical, radiation and mechanical 
  performance to previous owned antennas from other manufacturers with
  similar or better figures claimed in the technical specifications.

* 12 were delighted to see the new powerful balun and hi-power antenna
  capability. 5 of them beleive that the general lower noise and statics
is due to
  direct grounding of the balun and to the DC coil connected to the

* 68 were satisfied with the antenna but experienced difficulties in the
  assembly process ( with understanding that such large and complicated
  antenna needs extensive assembly and installation works ).

 Low points:

  It was interesting to see that almost all the criticism was
concentrated on 
the assembly concept and instruction manual.

* 56 would clearly prefer colour, numbering or any other markings for
  and faster identification of the large number of components.

* 48 were quite exhausted trying to ensure that the elements are
installed on
  the boom perfectly parallel and they are feeling that some kind of
  of the element to boom brackets and of the boom, will greatly reduce
  time and the efforts to messure the inter element  spacing and
  alignement and paralleling procedure. 20 of them do not understand how
  antenna of this class doesn't have such facility.

* 36 would prefer an improved graphic presentation and assembly manual
  23 clearly stated that simplified drawings of the components,
  check-list and assembly steps check-list, will greatly improve the
  enginering. 14 would prefere some simple drawings on installation tips
  issues. Also, 10 people are feeling that recommendations for use of
  materials should be more specific ( like the RTV and protective paints
) while
  8 expressed their prefference for an optional kit for coastal
installations with
  improved hardware quality.

* 9 peoples feel they want stronger and heavier pigtail wires.

* 5 are willing to see the antenna radiation lobes for the installation
  recommendations from the manual.


  Morel, 4X1AD          

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