QRZ! Ham Radio 4/QRZ Ham Radio Callsign Database - Volume 4.iso/digests/antenna/940171.txt

Internet Message Format | 1994-11-13 | 14KB

Date: Mon,  6 Jun 94 04:30:14 PDT
From: Ham-Ant Mailing List and Newsgroup <[e-mail]>
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Subject: Ham-Ant Digest V94 #171
To: Ham-Ant


Ham-Ant Digest              Mon,  6 Jun 94       Volume 94 : Issue  171

Today's Topics:
                    <<<Help--Mosley 40m add-on>>>
                           balloon (2 msgs)
                         Baloons and Antennas
            Curing RF Voltage on Rig case in Mob (3 msgs)
            Curing RF Voltage on Rig case in Mobile Units
                   Help Needed with Logyagi program
                   Impedence of a car radio antenna
                 need MFJ-941D tuner manual (3 msgs)
                 Want to hear your experience with AE
                             yes gutters

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We trust that readers are intelligent enough to realize that all text
herein consists of personal comments and does not represent the official
policies or positions of any party.  Your mileage may vary.  So there.
----------------------------------------------------------------------

Date: 5 Jun 1994 17:08:03 -0400
From: ihnp4.ucsd.edu!swrinde!gatech!udel!news.udel.edu!brahms.udel.edu![e-mail]
Subject: <<<Help--Mosley 40m add-on>>>
To: [e-mail]

I have a TA-33 up which must be about 20 years old but works fine.
I just ran into a TA-40-KR 40 meter add on kit. When we put it on, the
antenna analyzer showed that the SWR was way out of line on all the bands.
40 was nowhere to be seen, 20 was way off, others not quite so bad. This is
measuring on the ground.

Any ideas?   Tnx Bob


--
Bob Penneys, WN3K   Frankford Radio Club  Internet: [e-mail]
Work: Ham Radio Outlet (Delaware) [phone];  fax [phone]
Mail at home:  12 East Mill Station Drive   Newark, DE 19711  USA

------------------------------

Date: 5 Jun 94 19:18:58 GMT
From: [e-mail]
Subject: balloon
To: [e-mail]

Tried the "bat" kite and balloon antenna some time ago.
The kite requires some land, ie maybe only good at FD sites, etc.
We had fair results.  The kite was tested in Nove and snow on the
kite antenna causedg a large
static build up.  We had 600 ft of copper wire on for antenna, ditto the
balloon.  The balloon was used during FD as a 40 mtr antenna with tuner.
It worked well & better than a dipole on the site.  The balloon is
attracted to clouds and any wind will bring it down to about 10-20ft.
During the night we lost one of two balloons in higher wind.  The group
felt like it happened when the wind shifted directions.  Just insure if
you use a kite or balloon that any power lines are outside the radius
set by your wire length.
GL, Robert WB5CRG [e-mail]

PS,  I perfer the current type balun on the beams.  I tried a balun once
on the vertical with mixed results, tuned better but no sure about
performance.

------------------------------

Date: Sun, 5 Jun 1994 23:47:12 GMT
From: ihnp4.ucsd.edu!library.ucla.edu!csulb.edu!csus.edu!netcom.com![e-mail]
Subject: balloon
To: [e-mail]

Hey, if you're having trouble keeping it up with your whether balloon, try a
device more suited - a barrage balloon! These are easily obtained at your
nearest barrage sale...

------------------------------

Date: 6 Jun 94 01:41:46 GMT
From: [e-mail]
Subject: Baloons and Antennas
To: [e-mail]

> [e-mail] (Jim Grubs) writes:
>
> I tried it once. It wasn't worth the work it took to get it up.
>

That's what all the women say!

[yuk, yuk, yuk -- couldn't resist]

Pete WB6AZF/0

------------------------------

Date: 5 Jun 1994 18:46:39 GMT
From: news.delphi.com![e-mail]
Subject: Curing RF Voltage on Rig case in Mob
To: [e-mail]

Vince,

Try using the Radio Shack snap together 'square' choke kit. Wrap as many
turns of coax around it as possible, and use several choke if necessary.
These chokes took care of my stray RF problems. Be sure the coax shield is
ground at the antenna base also.


Andy N3LCW

------------------------------

Date: 5 Jun 1994 18:46:52 GMT
From: news.delphi.com![e-mail]
Subject: Curing RF Voltage on Rig case in Mob
To: [e-mail]

>Your mag mount aggravates the problem since
>it depends on who knows what amount of capacitance to achieve an RF ground.
>
>You can tell the *real* HF hams by the RF scars on their lips.  :-)
>
>73, KG7BK, [e-mail]
>
>
>
Mag mount for mobile HF work, YIKES! Put a ground strap from the shield at
the base of the mount and run it under the trunk, etc, to a screw to the
 car body. That should help. Use this WITH the chokes and you won't have a
problem any more.

Andy N3LCW

------------------------------

Date: 6 Jun 1994 02:06:36 GMT
From: ihnp4.ucsd.edu!usc!sol.ctr.columbia.edu!hamblin.math.byu.edu!news.byu.edu![e-mail]
Subject: Curing RF Voltage on Rig case in Mob
To: [e-mail]

: Try using the Radio Shack snap together 'square' choke kit. Wrap as many
: turns of coax around it as possible, and use several choke if necessary.
: These chokes took care of my stray RF problems. Be sure the coax shield is
: ground at the antenna base also.

Andy,
    I appreciate the time that both you and Cecil Moore have taken to
answer my question.  I am not sure though, whether you meant that the RF chokes
are to be put in the ground leg only going to the battery from the radio (near
the Radio) or in both that leg as well as the much shorter wire I also have
going from the rig case (wingnut) to a body ground as well.  I would like to
understand also, if you could explain, what the choke does.  I imagine (with
what little I know) that the choke provides a high inductance path thus looking
somewhat "open" to an RF signal but appearing as a short or ground for DC
current- but does this not create a condition where the RF potential at the rig
can be high then?  Obviously, I either just don't understand, or I don't have
the full story.  Its not that I doubt you at all (I plan on implementing it), to
the contrary, I would like to understand what is happening here.  I am currently
studying Electrical Engineering and am interested in learning from others with
experience- especially practical, such as yours.  Thank you for your time.

Vince Hadley
KA7GVQ
[e-mail]

------------------------------

Date: 6 Jun 1994 04:31:09 GMT
From: ihnp4.ucsd.edu!usc!howland.reston.ans.net!gatech!newsxfer.itd.umich.edu!jobone!ukma!asuvax!chnews![e-mail]
Subject: Curing RF Voltage on Rig case in Mobile Units
To: [e-mail]

Vince B. Hadley ([e-mail]) wrote:
: I am trying to solve a problem with RF Voltage on the Case of my TS-850S
: while running mobile. Vince Hadley

Hi again Vince, I just realized that I didn't tell you about my personal
most common cause of RF in the vehicle. With the adapters to convert the
so239 coax connectors to RG8 coax it is very easy to get one of the small
shield wires shorted to the center conductor... you can see how that can
cause RF on the mike. It is quite often intermittant so you may not be able
to find it with a multimeter. I was talking to Homer, Alaska and my signal
report suddenly dropped from S7 to S2. Dave could still read me so it was
not a dead short and with mobile SSB it's hard to tell that anything is
wrong. This time it wasn't QSB, it was a more than zero impedence short.

Those danged so239 connectors have caused me a lot of grief over the past
41 years. That's the first thing I suspect anymore.

73, KG7BK, [e-mail]

------------------------------

Date: 5 Jun 1994 20:56:02 -0400
From: ihnp4.ucsd.edu!swrinde!gatech!newsfeed.pitt.edu!dsinc!netnews.upenn.edu!netnews.cc.lehigh.edu!ns3.CC.Lehigh.EDU!ns1.CC.Lehigh.EDU![e-mail]
Subject: Help Needed with Logyagi program
To: [e-mail]

I resently Downloaded a program called LogYagi16.zip <or thereof>
and it's plans show a 4 element yagi with a dir and ref:

********************
  *******  *******
   ******  ******
    *****  *****
     ***o  o***    <--feedpoint
********************

but are the spacings in the middle feed elements, or just separated?
and what is the large thing on the bottom?
if anyone can help...thanks!!

DAvid
:)****************************************************************(:
**                                     **  The Flying HAm         **
**          David Roseman              **  [e-mail]        **
**       SysOp of NODE 3 BBS           **  [e-mail]   **
**                                     **                         **
** Cole's Law: Thinly sliced Cabbage   **                         **
********************************************************************

------------------------------

Date: Mon, 6 Jun 1994 07:01:57 GMT
From: ihnp4.ucsd.edu!library.ucla.edu!csulb.edu!csus.edu!netcom.com![e-mail]
Subject: Impedence of a car radio antenna
To: [e-mail]

In article <[e-mail]> [e-mail] (Bob Albert) writes:
>The impedance of a whip antenna for AM broadcast, such as one finds on
>most cars, is high.  The cable connecting it isn't coaxial cable, but a
>sort of shielded wire that has very low capacitance.
>
>Definitely not suitable for amateur radio use.
>
Many years ago, I once used the AM antenna on a Pinto for a 2 meter antenna.
Took a coax cable scrap (connector only one one end, around 18 inches long),
and soldered a female Motorola car radio connector on it, than used it to
connect the rig to the antenna.  Worked pretty well, and the rig's power
out indicator (which does measure it, not just a high/low display) showed
normal output power (which meant the antenna wasn't awful).  A ham friend
that I showed the cable to said that I probably made a reasonable matching
section of coax by luck, as the length appeared to be near 1/4 wavelength.
Not that familar with antenna theory, but I think such a length might
make loading a high impedance antenna possible with a rig expecting 50 ohms.

Anyone explain or expand on this?

------------------------------

Date: 5 Jun 1994 22:22:49 GMT
From: ihnp4.ucsd.edu!dog.ee.lbl.gov!agate!howland.reston.ans.net!gatech!news-feed-1.peachnet.edu!news.duke.edu!godot.cc.duq.edu!duq3.cc.duq.edu![e-mail]
Subject: need MFJ-941D tuner manual
To: [e-mail]

I got a used MFJ-941D versa tuner II and do not have the manual for
it.  I'd appreciate it if someone who has it can send me a copy of it
(is it a one page instruction sheet ?). or maybe just explain to me
via email how to use the tuner.

thanks in advance.

73s de jerry N3RKD

------------------------------

Date: Mon, 6 Jun 1994 00:10:14 GMT
From: netcomsv!netcom.com![e-mail]
Subject: need MFJ-941D tuner manual
To: [e-mail]

In article <2stj7p$[e-mail]> [e-mail] (Sy Jerry) writes:
>I got a used MFJ-941D versa tuner II and do not have the manual for
>it.  I'd appreciate it if someone who has it can send me a copy of it
>(is it a one page instruction sheet ?). or maybe just explain to me
>via email how to use the tuner.
>

Call MFJ and they will send you a manual on the latest model for free.  It
is probably very similar to the one you have since the current model is the
941E.  601-323-5869.q
--
Jim Chandler, N0VAH/AE
[e-mail]
p
v
941E.

------------------------------

Date: 6 Jun 1994 00:39:15 GMT
From: ihnp4.ucsd.edu!swrinde!cs.utexas.edu!asuvax!chnews![e-mail]
Subject: need MFJ-941D tuner manual
To: [e-mail]

James W Chandler III ([e-mail]) wrote:

: Call MFJ and they will send you a manual on the latest model for free.  It
: is probably very similar to the one you have since the current model is the
: 941E.  601-323-5869.q Jim Chandler, N0VAH/AE

Hi Jim, not very similar... The "D" version has a single needle meter
and the "E" has a dual needle meter... so half vastly different tuning
methods.

73, KG7BK, [e-mail]

------------------------------

Date: 5 Jun 1994 18:47:04 GMT
From: news.delphi.com![e-mail]
Subject: Want to hear your experience with AE
To: [e-mail]

RE: MFJ Loop,

The price and complaints on performance keep going up, stick w/AEA.

Andy N3LCW

ECSTATIC Isoloop user.

------------------------------

Date: 5 Jun 1994 16:17:09 -0700
From: ihnp4.ucsd.edu!swrinde!cs.utexas.edu!uwm.edu!reuter.cse.ogi.edu!netnews.nwnet.net!belnet.bellevue.k12.wa.us!belnet.bellevue.k12.wa.us![e-mail]
Subject: yes gutters
To: [e-mail]

I've used gutters via the heath tuner in years past.  I've used metal
chimneys and duct work in apartments.  All have worked to some extent.

------------------------------

End of Ham-Ant Digest V94 #171
******************************