W8JITom@aol.com wrote:
>>I purchased a used MB-V-A, the unit had burned sections of tinned
>> copper braid between the terminals and the components.
> 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.
Thanks for you comments, Tom. Perhaps I should replace the braid
with teflon covered wire...not sure of the spec. but I have seen it
used in a high power 4:1 balun. Where could I purchase this?
I have been pleased with the Viking MB-V-A, as I always get a
perfect match (only using coax to coax at present), and I have
removed a coax switch and PWR/SWR bridge from the desk.
I am interested in two comments you made recently about this model:
1. The circuit is described a *pi* and uses a fixed cap. on the
TX side, variable inductor to ground, and variable cap. on the
antenna side. I suppose this avoids having three variables to adjust.
You have said that it does't really operate as a pi on the lower bands?
I have found the harmonic attenuation to be excellent, and it has
enabled me to get a clean report from the local Radio Inspector
using a spectrum analyser. Operating direct, the spectrum analyser
showed some low level output on 56MHz when I operated on 14Mhz (also
using a Bencher Lo-pass filter).
2. The limitation you mentioned was on the low bands into
a low impedance. I am planning a half wave dipole on 160M with
ladderline, and wish to also use it on 80M.
I will put an external balun outside the house, and bring coax to
the tuner (< 2m), and avoid using the balun in the tuner.
Do you think this will be successful?
Thanks for your comments,
Martin ZL1ANJ
>From morel.grunberg@telrad.co.il (Morel Grunberg) Thu Jan 16 13:08:51 1997
From: morel.grunberg@telrad.co.il (Morel Grunberg) (Morel Grunberg)
Subject: Hy-Gain TH-11DX beam: opinions summary
Message-ID:
<c=US%a=_%p=TELRAD%l=MISMAIL-970116130851Z-174@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
traffic 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 guywires 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 BN-4000.
* 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
easier
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
pre-drilling of the element to boom brackets and of the boom, will
greatly
reduce the time and the efforts to messure the inter element spacing
and
exhaustive alignement and paralleling procedure. 20 of them do not
understand how an antenna of this class doesn't have such facility.
* 36 would prefer an improved graphic presentation and assembly manual
while 23 clearly stated that simplified drawings of the components,
component check-list and assembly steps check-list, will greatly
improve
the human enginering. 14 would prefere some simple drawings on
installation tips issues. Also, 10 people are feeling that
recommendations
for use of some 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.
73,
Morel, 4X1AD
>From dippel@rrze.uni-erlangen.de (Dieter Dippel) Thu Jan 16 15:49:03 1997
From: dippel@rrze.uni-erlangen.de (Dieter Dippel) (Dieter Dippel)
Subject: WAE-Contest 96: Scores available
Message-ID: <16BE954EA@isis.rrze.uni-erlangen.de>
Hello everybody,
the Contest-Scores of the WAE-Contest 1996 CW are available
on the Bavarian Contest Club Homepage.
pse try http://www.rrze.uni-erlangen.de/~unrz45/BCC
73 de Dieter, DF4RD
[] name: Dieter DIPPEL, amateur-radio-callsign: DF4RD
[] university: Erlangen-Nuernberg, Regional Computing Centre
[] address: Martensstrasse 1, D-91058 Erlangen
[] phone: +49 (0) 9131 85-7030 fax: +49 (0) 9131 30 29 41
[] internet: dippel@rrze.uni-erlangen.de
[] www: http://www.rrze.uni-erlangen.de/~unrz45/
[] packet: DF4RD@DB0BOX.#BAY.DEU.EU
>From w2up@voicenet.com (Barry Kutner) Thu Jan 16 15:24:50 1997
From: w2up@voicenet.com (Barry Kutner) (Barry Kutner)
Subject: RFI filter?
Message-ID: <199701161528.KAA02120@mail3.voicenet.com>
Does anyone have info about the RFI filter that appears on p. 122 in
Feb. QST?
Tnx/Barry
--
Barry Kutner, W2UP Internet: w2up@voicenet.com
Newtown, PA FRC alternate: barry@w2up.wells.com
>From dave@egh.com (David Clemons) Thu Jan 16 16:31:51 1997
From: dave@egh.com (David Clemons) (David Clemons)
Subject: needed: e-mail address for NAQP SSB team registration
Message-ID: <Pine.LNX.3.91.970116112828.3095C-100000@newman.egh.com>
Hi,
Who do I send a team registration to for the NAQP SSB contest?
73, Dave Clemons K1VUT
>From kurscj@oampc12.csg.mot.com (Chad Kurszewski WE9V) Thu Jan 16 16:44:07
>1997
From: kurscj@oampc12.csg.mot.com (Chad Kurszewski WE9V) (Chad Kurszewski WE9V)
Subject: needed: e-mail address for NAQP SSB team registration
Message-ID: <2.2.32.19970116164407.006a11f4@oampc12.csg.mot.com>
> Who do I send a team registration to for the NAQP SSB contest?
>73, Dave Clemons K1VUT
The answer:
> Numerous people have just asked if I will again be taking NAQP CW
>submissions electronically. The following excerpt is from my 5 Jan posting:
>
>>
>> 1. Please send your NAQP Team pre-registrations in prior to the
>>start of the contest. Send CW Teams to me, K6ZZ (w9nq@ccis.com) and SSB to
>>Steve, K6AW (merchant@silcom.com).
>>
>> 2. We will both be accepting E-Mail log submissions again at the
>>addresses listed. Send your complete Log and Summary Sheet in ASCII Text
>>format. Please, no binary or special format files.
>>
>
>Etc...
>
> One additional note about submitting electronic logs, if you use
>attached files to E-Mail messages, name the files with your callsign in
>them. Ie, K6ZZ.LOG and K6ZZ.SUM or K6ZZ.ALL. If everyone names their file
>NAQPCW.LOG it makes it a bit difficult to sort things out. Hopes this helps.
>
>73, Bob K6ZZ
---
Chad Kurszewski, WE9V e-mail: Chad_Kurszewski@csg.mot.com
The Official "Sultans of Shwing" Web Site: http://www.QTH.com/sos
>From gog@alpha.isan.troitsk.ru (???) Thu Jan 16 17:52:54 1997
From: gog@alpha.isan.troitsk.ru (???) (???)
Subject: need result WPX 96
Message-ID: <199701161752.UAA02164@alpha.isan.troitsk.ru>
Hello !
i looking scores on WPX 96 cw and ssb . SOSB LP on 80 mtr.
tnx for read this msg.
73 de ra3dfp Oleg
>From larrytx@co.intel.com (LarryX Tyree contractor for brentc) Thu Jan 16
>18:02:38 1997
From: larrytx@co.intel.com (LarryX Tyree contractor for brentc) (LarryX Tyree
contractor for brentc)
Subject: Math lesson
Message-ID: <9701161802.AA25817@ark.co.intel.com>
Many thanks to those of you who have responded to the request for
your Internet Sprint logs. However, we still have a large percentage
of logs missing, and this is making the name tracings very difficult.
In fact, the percentages are so low this time, we just are not going to
include the name tracings in the results.
Here is the math:
A trace gets lost when it goes through two consecutive non-submitters.
The probability that a Q is with a non-sub is 1 - PctMatch. With two
consecutive non-subs it's (1 - PctMatch) ^ 2; that's the probability
that a trace will get lost at any hop along the way.
The probability that a trace will continue at any hop is one minus that:
1 - ((1 - PctMatch) ^ 2)
The probability that a trace will continue for N consecutive hops is that
raised to the Nth power:
(1 - ((1 - PctMatch) ^ 2)) ^ N
The average trace length is found for solving that expression for N when
the expression's value equals 50%.
Let's do some math:
PctMatch .95 .9 .8
1 - PctMatch .05 .1 .2
( 1 - PctMatch ) ^ 2 .0025 .01 .04
1 - ( ( 1 - PctMatch ) ^ 2 ) .9975 .99 .96 = Y
( 1 - ( ( 1 - PctMatch ) ^ 2 ) ) ^ N = 50% 277 69 17 = X
Check it by raising base Y to the X power on your HP.
So when PctMatch drops from 0.95 to 0.8, the work goes up by a factor
of (277 / 17) = 16! Also, (0.04 / 0.0025) = 16.
Whenever PctMatch is above, say, 92 percent, We'll do name traces.
We will wait another few days and publish what we have then.
73 Tree N6TR
tree@contesting.com
>From k4ro@music-city.tdec.state.tn.us (K4RO - Kirk Pickering) Thu Jan 16
>18:31:03 1997
From: k4ro@music-city.tdec.state.tn.us (K4RO - Kirk Pickering) (K4RO - Kirk
Pickering)
Subject: Amps in LP tests?
Message-ID: <9701161831.AA13690@music-city.tdec.state.tn.us.state.tn.us>
Curious about this one. Ol' Jim K4OJ noted the use of an amplifier
in the NAQP to bring his power output from 75w to the allowed 150w,
and said he noted a big difference.
I'm curious how many other folks use amps in a low power contest
such as the NAQP?
Let's be real clear on one thing. I think Jim's a great guy and a
great op. I am not implying in any way that he is voilating any
rules or doing anything wrong whatsoever. No lynchmob mentality, please.
I'm not looking for a vote "for" or "against" the use of amps in NAQP
or other LP contests. That's not the reason for this post.
The reason for this post is that I am curious how many other folks
use their amps in these contests. I have a 500w amp, but will probably
not ever use it in NAQP, because everything is automatic except the amp.
Using the amp would slow things down and eliminate the 'automatic' in
my band/antenna swithching arrangement. Now if I had a solid state or
auto-tune amp of some sort... that might be a different story. My rig
can put out 100w all day long, and I wonder if I'd see any real
difference going to 150w output. I wonder why the low power tests
have the limit at 150w when 95% of xcvrs are 100w output.
Guess this is another reason to have a 200W output xcvr. :-)
Anyone got a good clean FT-1000D for sale? (email me...)
-Kirk K4RO in Pegram, TN < k4ro@music-city.tdec.state.tn.us >
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