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Old 18-12-2009, 10:12   #16
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Bill,
How far off do the standoffs on the antenna lead wire need to be from the uninsulated portion of a backstay antenna? Would this same distance be needed for tuner-to-seacock ground foil from any DC ground?

Paul L
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Old 18-12-2009, 10:21   #17
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Paul,

It's really hard to answer that Q with specificity. I've seen (and had) installations with the GTO-15 wire just tied off to the uninsulated portion of the backstay, and they seemed to work pretty well.

However, in theory it IS a good idea to maintain some separation. I use solid nylon rods, about 1.5" long, with a hole drilled thru the middle. Then, a simple wire tie will hole the feedwire 1.5" off the uninsulated portion of the backstay. Looks good and seems to work great.

Truth is, however, I really prefer to feed the entire backstay from underdeck, at the chainplate, putting just one insulator near the top of the backstay. This has several advantages: (1) efficiency; (2) no lossy GTO-15 run; (3) no hole thru the deck; (4) simple and secure connection at chainplate; much less expenive since only one insulator is required; etc., etc. The one downside, if you're worried about "RF burns" -- a much overestimated danger IMHO -- you can put a PVC or nylon boot over the lower part of the backstay.

The distancing from other DC wires is a different critter. In the first instance, you're mostly worried about energy loss and detuning. With other DC wires, you're mostly concerned about RFI, both to and from the groundstrap.

Bill
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Old 18-12-2009, 10:59   #18
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Originally Posted by btrayfors View Post
It's really hard to answer that Q with specificity.....
Thanks for trying.
If the uninsulated portion of the backstay is tied to the bonding system, which eventually ties to the DC ground, why would it not also have RFI issues?
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Originally Posted by btrayfors View Post
The distancing from other DC wires is a different critter. In the first instance, you're mostly worried about energy loss and detuning. With other DC wires, you're mostly concerned about RFI, both to and from the groundstrap.
Bill
I was trying to figure out how convoluted a path I might need to go from the tuner to the the thru hull. Right now it is pretty well separated from all DC circuits except where it passes behind a heater with grounded frame. I believe I am getting some ground loops the way my LEDs change brightness and my computer occasionally reboots.

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Old 18-12-2009, 11:22   #19
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Quote:
Originally Posted by Paul L View Post
Thanks for trying.
If the uninsulated portion of the backstay is tied to the bonding system, which eventually ties to the DC ground, why would it not also have RFI issues?

I was trying to figure out how convoluted a path I might need to go from the tuner to the the thru hull. Right now it is pretty well separated from all DC circuits except where it passes behind a heater with grounded frame. I believe I am getting some ground loops the way my LEDs change brightness and my computer occasionally reboots.
Paul L
(backstay) It might. Use the standoff insulators.


(RFI issues) Might or might not be just ground loops. How are you getting power to the transceiver? Do you have AWG6 wire directly to the house batteries?

Is the radio itself tied into the RF ground system, or just the tuner? It should be just the tuner, regardless of what is said in the "instructions". Grounding the radio separately to the RF ground system very often creates ground loop problems.

The liberal use of clamp-on ferrites on the ends of coax, power, and control cables might help.

B.
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Old 18-12-2009, 11:27   #20
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(backstay) It might. Use the standoff insulators.


Might not be ground loops. How are you getting power to the transceiver? Do you have AWG6 wire directly to the house batteries?

The liberal use of clamp-on ferrites on the ends of coax, power, and control cables might help.

B.
Bill
The transceiver uses AWG6 to the distribution bars next to the battery and then to the smaller ICOM power cable. It should be clean. I will try adding ferrites around the system. It definitely seems to be worse at higher frequencies. Thanks for the response.

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Old 18-12-2009, 18:14   #21
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Hello All,

I recently purchased an ICOM 802 Transceiver and AT-140 tuner. I have everything hooked up right now but I don't seem to be getting good reception. The antenna is clamped to the insulated backstay and I'm using my lifelines for a ground for now. I was grounded to my bronze through hull earlier but having it connected or not made little difference. I am only trying to receive right now, not transmit. I have heard a bit of shortwave radio at night in 6 Mhz range and I did hear the southbound 2 wx report from Herb in Ontario at 12.359 Mhz this afternoon.

Is the grounding important for receiving?

I am on the west coast of Canada tied up to a dock in a bit of a fjord, does this matter?

What can I expect to hear?

Thanks in advance,

Brennan
Hello Brennan,

Here is a link to Richard Mogford's excellent article on HF radio (It could anchored in a Sticky) :-
HF Radio at Sea
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Old 18-12-2009, 18:51   #22
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Bill,

Just a quick add to your post :-

Brennan, makes sure that the tuner is grounded. And make sure that coax cable is not used to connect the tuner to the backstay - this should be a heavy gauge tinned copper wire sheathed in rubber, this wire forms part of the antenna - total length is measured from the tuner to the top insulator on the backstay.
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Old 18-12-2009, 18:52   #23
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I bet no ground is ok for receive. I have no grounding on my receiver - radiofax everywhere and voice from the other side of the world without any problem.

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Old 21-12-2009, 22:20   #24
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Thanks for all the info. Unfortunately I'm away from the boat for a few months, so the HF radio experimentation will have to wait. Next time I will sail away from the marina and get out into the open water.

To answer some questions, I'm using RG8x from the transceiver to the tuner. I stripped and crimped on the connectors myself. I used a multimeter to ensure I didn't have any shorts and had good continuity. I still need to get some GTO-15 wire with standoffs from the tuner to the back stay, just using insulated copper for now. Having the tuner and the transceiver grounded or not makes very little difference with the reception. I'm sure it will when I transmit.....

Thanks,

Brennan
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Old 21-12-2009, 23:32   #25
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I don't understand why you would not want to ground the radio, when in Icom installation instructions it specifically says tuner and radio MUST be grounded properly to one ground point.
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Old 22-12-2009, 00:14   #26
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If you are having receive problems, it is more likely a high noise level than a ground issue. The marina may be the source, but if you still have problems outside the marina you need to isolate the source of the local noise by turning everything on and off. One of the worst cases I've seen was a digital voltmeter in the electrical panel...
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Old 22-12-2009, 11:01   #27
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Stand off

Hey,

I used 4" PVC tube (bathroom sink water tubing) big enough to get a zip tie through and went through the tube around the GTO and back through the tube and zipped it to the back stay and spaced them to support it till it got to the threw the deck fitting. It works so ----

Gary
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Old 23-12-2009, 01:20   #28
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Originally Posted by highseas View Post
I don't understand why you would not want to ground the radio, when in Icom installation instructions it specifically says tuner and radio MUST be grounded properly to one ground point.
I'm just using my lifelines for a temporary ground until I can install copper foil or mesh under the sole...
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Old 23-12-2009, 21:20   #29
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SSB Reception, etc.

Quote:
Originally Posted by Cirruscloud View Post
I am only trying to receive right now, not transmit. I have heard a bit of shortwave radio at night in 6 Mhz range and I did hear the southbound 2 wx report from Herb in Ontario at 12.359 Mhz this afternoon.
Is the grounding important for receiving?
I am on the west coast of Canada tied up to a dock in a bit of a fjord, does this matter?
What can I expect to hear?
Brennen,
Sorry I'm coming in late to this......but, perhaps I can shep a bit of clarity onto the problem????

You seem to afflicted with an all too common trouble:
"Can't hear much-itis".....
It's not "terminal", and is usually easy and cheap to fix.....
(see below for some details)

1) First off , please take Bill's advice and counsel......he does know his stuff....

2) Next, a few brief answers to your specific questions....(and then some details on what, where, and when to receive from your set-up)

a) No, grounding is typically not important at all for receiving.....(although in rare occasions, it may provide some measure of noise reduction, typically it is a non-issue)

b) In a fjord???? probably not the best location....and you'll find better results at sea......but, you're still better off than many hf radio users....like the hams using HF radio in apartments worldwide, etc....
So the fjord isn't that big of a hinderence....

c) Tied to a dock.....
AH....Now, were getting closer to the root of the problem....
Being tied to a dock, means you're near shore, and near all the horrible noise sources (radio noise sources) that can drown out all but the strongest HF radio signals......

And, if you're in a marina or yacht club....or at any dock with other boats around you.....You are in the worst possible location for HF radio reception.....
All of the battery chargers, inverters, refrigeration units, air ionizers, fans, pumps, bilge pump sensors, computers, power supplies, solar charge controllers, wind generators, etc.....and the heaters, thermostats, blower motors, etc......not to mention the engines and gensets, etc.....
The list goes on and on......but, you get the idea.....

You need to get away from all of those "noise sources" to hear weaker signals......and that's actually a very easy fix!!!!


Quote:
What can I expect to hear?
3) The good news is, that you ARE already hearing a fairly low-powered (150 watt) signal from 2000 miles away.....you're hearing Herb on 12.359mhz.....and he's usually got a slight directional signal, pointing Eastward (away from you), and isn't the strongest signal around......
So, that's actaully great news that you're hearing him!!!

Next is the what, where, and when.....
HF radio weather braodcasts (voice, fax, or text) are NOT sent out 24/7 on all channels/frequencies.....
You will need to tune to the proper frequency/channel, at the scheduled broadcast times, in order to receive the broadcast....

a) For voice weather.....
Have a look at the USCG Voice Weather Broadcast times and frequencies here:
USCG HF Voice
You should be able to receive the NMC (Pt. Reyes, CA) on at least one or two of those frequencies, depending what time of day you're tuning in....
Try 8764 (ch. 816) first, day or night...and if no joy, then try the other designated frequencies/channels.....
(you may also hear NOJ, Kodiak, AK as well....)

And , for other voice weather, have a listen to Shipcom Radio, WLO (mobile, AL) and KLB (near Seattle, WA).....
They send weather for Pacific, N. Atlantic, Carib, and Gulf of Mexico, from BOTH of their transmitter locations, multiple times each day....
Have a look at their schedules here:
HF SSB Radiotelephone, Telex and Email Frequencies and Channels
ShipCom LLC :: Marine HF Radiotelephone and HF Single SideBand Email
You should hear their KLB station very well.....

b) For WeFax (weather charts).....
You should also be able to receive USCG NMC (Pt. Reyes, CA) wefax transmissions......have a look here for details...
NWS Radiofax
http://weather.noaa.gov/pub/fax/hfreyes.txt
Try 8682 first....and then tune the other frequencies as needed....
(You also may find NOJ, Kodiak, AK wefax broadcasts to be useful as well...)

And, in addition to Canada's CFH, braodcasts from Nova Scotia, you have VFA (Inuvik), VFF (Iqaluit, NWT) and VFR (Resloute).....all broadcasting wefax.....
See the worldwide schedule here:
http://www.nws.noaa.gov/om/marine/rfax.pdf

c) For text weather.....
You should also be able to rceive NMC (Pt. Reyes, CA) radiotext (SITOR) weather broadcats.....have a look here:
USCG HF SITOR


d) You may also find other (ham radio, etc.) sources of info, weather, news, communications, etc. to be useful to tune into....
Try the Maritime Mobile Service Net, on the 20 meter ham radio band, at 14.300mhz.....almost anytime...but mainly from 9am PST thru 9pm PST..
Maritime Mobile Service Network



4) PLEASE, don't give up on your HF radio....it DOES work!!!

Quote:
Better yet, skip the archaic HF radio all together and use dial up through a sat phone to get GRIB files. If I were in a remote inlet somewhere up the inside passage, would I be able to call for help with this thing?
Brennen, HF radio is NOT archaic at all......you just need to learn some of its uses (and particulars) before becoming proficient at it....
I've been doing this for 35 years....but, it will NOT take that long!!!! Believe me, you'll get the hang of it quickly.....I just suspect that nobody has ever explained it all to you......until now....

And, the answer is: YES....
Yes, if you were in a remote inlet somewhere, you WOULD be able to use this thing to call you help......it's actually going to be your best way to call for help, and maybe your only way.....except for a new EPIRB, the Ico M802 (properly installed) is a very reliable piece of "saftey gear".....
No question about it.....


5) To sum up....
Get away from the marina, listen at the scheduled times on the correct frequencies / channels, and you should hear quite a bit.....
And, we'll cover the details on transmitting and "optimal" frequencies / channels, later on....

{Oh, one last point....don't sweat the "stand-offs" for the GTO-15 wire.....if the lower part of yoru stay (below the bottom insulator) is NOT grounded, the stand-offs won't make a difference......if the lower part IS grounded, simply remove the grounding wire, and all is well with the world...}

I do hope this helps.....if not, please continue to ask questions.....and we'll be here to help....

Fair winds...

John
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Old 24-12-2009, 19:37   #30
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John,

Thanks for all the information and the encouragement. I'm looking forward to getting back to the boat in a few months to finish the installation and use the radio some more. Its good to know that I will be able to hear a clear signal at some point. Especially after spending a fair bit of money on a transceiver and tuner.

Brennan
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