In article ,
"Charlie J" wrote:

Gary was proposing a significant departure from "conventional wisdom" in
recommending the placement of the antenna coupler/tuner closer to the
counterpoise/rf ground than is conventionally done. I asked if there was
any objective evidence that showed that placing the antenna coupler/tuner
immediately adjacent to the counterpoise half of the antenna system truly
offered measurable improvement, on a non-metal pleasure boat... today.

Charlie,
Counterpoise is a non-issue in MF/HF Marine Radio systems as most of
the "non-metal pleasure boat" vessels aren't large enough to have such
a thing installed. To be effective the "Counterpoise" would have to be
1/4 Wavelength at the lowest operating frequency. Say 2182.0 Khz.
That would be around 90 ft or so and that's much longer than the hulls
we are talking about. Also consider that if one could build a
counterpoise Rf Ground system onboard a plastic hulled vessel, the
couterpoise would be raditaing half the applied power from the
Transmitter into everything that was capacativly coupled to the devised
counterpoise. Then in a mutiple Frequency installation that most Marine
Radio systems are, to be effective, a couterpoise Rf ground system would
need a tuned element for each band segment of the system. the autotuner
takes care of the antenna side but what tunes the couterpoise for each
different frequency? It does need to be tuned to be an effective
"counterpoise" So forget counterpoise. Now, concider "Coupling to the
Seawater" for effective RF Ground. the Seawater is an effenctive low
impedance Rf Ground that is nonreactive across the MF/HF Specturm.
It doesn't need to be tuned. Get out your (if you have one) RF Network
Impedance Bridge, and sweep the MF/HF Spectrum of a well coupled
Seawater RF Ground System, on a Plastic (non-matalic hulled) Vessel.
Then come back and tell us about what you have found. We would be
interested in what your "conventinal wisdom" would be after undertaking
some rather basic experimentation.

Yes, having the autotuner as close to the RF Ground System is one
of the Basic Critical Rules, that your "conventional wisdom" doesn't
even consider, to is detriment. Simplistic "conventional wisdom"
just leeds to "the blind leading the blind" metality, and perpetuates
Junk Knowledge. I see you are a ham, so you must have some rudimentary
knowledge of RF Physics. RF Network Analysers were invented to allow
folks to quanitfy the complex impedance of RF systems, so that even
non-RF Engineering types could figure this stuff out, emperically,
rather than on a Mathamatical Formula, that could only guestimate what
was actually happening.

In Marine Radio Systems on Plastic Hulled Vessels, antenna system
compromises are preety much the order of the day as space and length
just aren't available for anything that comes close to Ideal criteria.

Your experiences may be different than mine, but the Basic Laws of
Physic's don't and haven't changed since Marconi, and after all he did
Invent the Marconi Antenna System that we are all trying to duplicate on
the vessels.

Bruce in alaska
--
add a 2 before @

Followup to msg on Tue, 27 Jan 2004 22:58:36 GMT, Gary Schafer
:
(Original msg on bottom)

May I put down a slightly different argument om this tread ?

I have to reinstall, on a new boat, my HF TX, with manual tuner and
insulated backstay, and I would like to minimize the generation of RFI
on the other boat circuits. The first time this costed to me a one
week hunting for coupled wires and chockes filters spread all around.

Then, for what the terms of this discussion are concerned, being
involved, according to my understanding, three items : the TX, the
tuner and the feeding line interconnecting them, what is the best
relative positioning . for minimize RFI? And do you have other
recommendations?

Sorry for the little OT.

Best regards

Manlio
IK2RAU

Manlio Laschena
http://Delphi-Jedi.org

In article ,
Manlio Laschena wrote:

Followup to msg on Tue, 27 Jan 2004 22:58:36 GMT, Gary Schafer
:
(Original msg on bottom)

May I put down a slightly different argument om this tread ?

I have to reinstall, on a new boat, my HF TX, with manual tuner and
insulated backstay, and I would like to minimize the generation of RFI
on the other boat circuits. The first time this costed to me a one
week hunting for coupled wires and chockes filters spread all around.

Then, for what the terms of this discussion are concerned, being
involved, according to my understanding, three items : the TX, the
tuner and the feeding line interconnecting them, what is the best
relative positioning . for minimize RFI? And do you have other
recommendations?

Sorry for the little OT.

Best regards

Manlio
IK2RAU

Manlio Laschena
http://Delphi-Jedi.org

Manlio,

Does the antenna tuner have channelized presets for each channel
used, or is it totally manually tuned? The answers for best
installation can only be given if we have all the facts concerning
the individual operations of each of the pieces of equipment.
Is the transmitter channelized? does it channel the presets in the
tuner to match the channels of the transmitter, if the tuner is
channelized? what is the make and model of the tuner and transmitter?


Bruce in alaska
--
add a 2 before @

Followup to msg on Sat, 31 Jan 2004 20:56:29 GMT, Bruce in Alaska
:
(Original msg on bottom)

Thanks Bruce for answering.
The TX is an old TS430S and the tuner is a manual tuner 1.8 - 30 MHz
with band steps and continous tuning.
My first installation, several years ago, had a good success for what
SWR is concerned and TX efficiency. The problem of RFI was solved with
chokes and cap around the DC circuitry on board.

Any other info available on your request.
Thanks again and 73
IK2RAU
Manlio


Does the antenna tuner have channelized presets for each channel
used, or is it totally manually tuned? The answers for best
installation can only be given if we have all the facts concerning
the individual operations of each of the pieces of equipment.
Is the transmitter channelized? does it channel the presets in the
tuner to match the channels of the transmitter, if the tuner is
channelized? what is the make and model of the tuner and transmitter?


Bruce in alaska

Manlio Laschena
http://Delphi-Jedi.org

Followup to msg on Sat, 31 Jan 2004 20:56:29 GMT, Bruce in Alaska
:
(Original msg on bottom)

Thanks Bruce for answering.
The TX is an old TS430S and the tuner is a manual tuner 1.8 - 30 MHz
with band steps and continous tuning.
My first installation, several years ago, had a good success for what
SWR is concerned and TX efficiency. The problem of RFI was solved with
chokes and cap around the DC circuitry on board.

Any other info available on your request.
Thanks again and 73
IK2RAU
Manlio


Does the antenna tuner have channelized presets for each channel
used, or is it totally manually tuned? The answers for best
installation can only be given if we have all the facts concerning
the individual operations of each of the pieces of equipment.
Is the transmitter channelized? does it channel the presets in the
tuner to match the channels of the transmitter, if the tuner is
channelized? what is the make and model of the tuner and transmitter?


Bruce in alaska

Manlio Laschena
http://Delphi-Jedi.org

Followup to msg on Sat, 31 Jan 2004 20:56:29 GMT, Bruce in Alaska
:
(Original msg on bottom)
this may be duplicate msg, but I have some problem on the net.

Thanks Bruce for answering.
The TX is an old TS430S and the tuner is a manual tuner 1.8 - 30 MHz
with band steps and continous tuning.
My first installation, several years ago, had a good success for what
SWR is concerned and TX efficiency. The problem of RFI was solved with
chokes and cap around the DC circuitry on board.

Any other info available on your request.
Thanks again and 73
IK2RAU
Manlio

Does the antenna tuner have channelized presets for each channel
used, or is it totally manually tuned? The answers for best
installation can only be given if we have all the facts concerning
the individual operations of each of the pieces of equipment.
Is the transmitter channelized? does it channel the presets in the
tuner to match the channels of the transmitter, if the tuner is
channelized? what is the make and model of the tuner and transmitter?


Bruce in alaska

Manlio Laschena
http://Delphi-Jedi.org