LMR-400

[a64pilot]

Why not just use the terminal end for the GTO that the tuner comes with? I was just planning a crimp connection to that terminal ring. I wanted just one insulator and to tie the GTO to the chainplate, but Mack Sails was adamant about it being a safety issue and pretty much refused, so I have two insulators, one just above the Bimini and the other about six ‘ from the mast.
There will be significant length of the GTO in my installation since I’m not connecting to the chainplate. To shorten the length of the GTO would mean an increase on ground length. Currently ground strap is only about 5’ long to the large Dynaplate Frankly sold me.
Sort of confuses me using strap and connecting the corner of the strap to the tiny ground screw on the tuner.

By the way, inside of the AT-140 there is a very small toggle switch. What is it’s function?

[a64pilot]

Originally Posted by Kenomac

I haven't used my SSB even once over the past six years. Please let me know when you get yours hooked up so we can test them.

Be a week I’d guess as I have ordered the Coax and will need to do some reading after the install. Then we need to pick a time of course and a freq.
I would be surprised if we could communicate though, that is a long ways.
I have little to no idea of what I’m doing with a HF radio, only rarely used one in the Military years ago and I think these radios are significantly different.

[TreblePlink]

With the bottom insulator that high you don't have much choice. Absent morons on board, I personally don't feel it's a safety issue given the relatively rare time spent transmitting. Skin contact during transmit will not shock at all, but can result in a minor burn at 100 watts. I once experienced a burn from a 10,000 watt transmitter - it was not serious.

Having said that, RF exposure of any kind is today a hot-button issue and there are many alarmist critics. 100 watts ssb, intermittent transmit, should be well under regulatory maximum permissible exposure thresholds.

If you were to forego the bottom insulator and rely on the boat's fiberglass, the impedance may change under wet conditions - the tuner may or may not deal with that ok.

Good luck, it sounds like you're on the right track.

[SV Bacchus]

Originally Posted by a64pilot

I would be surprised if we could communicate though, that is a long ways.

I am a novice and know nothing other than what I have heard. Don't these radios communicate world-wide by bouncing signals off the Strato? I believe it can be hit or miss to fine tune the wave length to hit someone in a particular spot.

Whew, I need to take the class..

[Frankly]

The two insulator backstay will work fine (used that setup for 12 years) just trying to simplify things a little (the reason I got rid of your Dynaplate). If you can find a small SS clamp for the wire above the insulator then you can keep an eye on the connection from time to time. Put some electrical tape over it.

The reason for the paradox of small antenna wire vice ground foil is it all starts at the tuner. The radiating antenna half starts at that tuner insulator, because you typically can't locate the tuner near the seawater connection use the lowest impedance connection you can get for that run (IE foil connection).

HF SSB will communicate world over just not all the time, and all places, and all frequencies. I have talked to Hawaii hanging on my dock on rare conditions (14 Mhz) but would not count on doing it every night. Sunspot activity also has a big part. Most used marine HF frequencies in the 7 to 10 Mhz range can get you a thousand miles or so sometime during the 24 hour cycle.

I always make the Admiral get in the opposite corner of the cockpit when I am using the SSB and she is on watch. Can't be too careful messing with radiation.

[TreblePlink]

A couple other bits and pieces ...

Indeed "SSB" mode, because of the frequencies chosen, can often propagate thousands of miles. The choice of 4 or 6, or 8 MHz etc influences distance and favorable time of day. Experienced Ham Radio guys are very familiar with this.

One other point regarding RF safety and alarmists; because of the proximity of the backstay antenna to the mast, shrouds, and even DC wiring, it is not at all uncommon to touch one of these while someone is transmitting, and discover that they are "hot" to the touch. Not dangerous, but it can get your attention.

[a64pilot]

anyone know what the small toggle switch inside the AT-104’s function is?

[a64pilot]

Originally Posted by SV Bacchus

I am a novice and know nothing other than what I have heard. Don't these radios communicate world-wide by bouncing signals off the Strato? I believe it can be hit or miss to fine tune the wave length to hit someone in a particular spot.



Whew, I need to take the class..

Way back when, mid 70’s CB’s were popular. A few of us had linear amplifiers etc to enhance performance. A friend even had twin 150’ crankup towers with Moonraker 4 antennas and I have no idea what kind of power, he was a Ham and even back then was playing with video I believe.

Anyway very, very rarely usually late at night in my truck when the “skip” was rolling I could get out quite far with my little 50W linear. One time supposedly all the way to California from Georgia. I say supposedly as not everyone tells the truth, so who knows.
It was a little odd cause you never knew how far you could get out, you may get out fine to 500 miles and talk fine, but not be able to do 50 miles, and get great modulation now, then ten minutes from now, get nothing at all.

Also I think maybe that now we are in a period of higher than normal sun spot activity and that has a tendency to shut down long range commo, I assume due to noise? I don’t know about sun spot activity, I think I read that somewhere though.
It runs in a cycle, about ten years?

[svinshallah]

If I remember correctly it’s for radios that have a higher control voltage, ie non-ICOM radios.

[a64pilot]

Originally Posted by svinshallah

If I remember correctly it’s for radios that have a higher control voltage, ie non-ICOM radios.

Thanks, I had no idea and hadn’t noticed anything in the books about it, probably missed it

[Dsanduril]

During automatic tuning, the AT-140 grounds the key voltage line, and the HF transceiver reduces output power.

If the key voltage is more than 8 V, switch the [MODE] switch (S1) to OFF mode (lower position).

As noted, 802 shouldn't require any changes.

[Wotname]

Originally Posted by SV Bacchus

I am a novice and know nothing other than what I have heard. Don't these radios communicate world-wide by bouncing signals off the Strato? I believe it can be hit or miss to fine tune the wave length to hit someone in a particular spot.

Whew, I need to take the class..

FWIW, it is the ionosphere rather than the stratosphere and the ionosphere changes daily (night / day) and monthly / yearly. Sunspots have a great affect on the ionosphere.

[SoonerSailor]

Originally Posted by a64pilot

Way back when, mid 70’s CB’s were popular. A few of us had linear amplifiers...

Anyway very, very rarely usually late at night in my truck when the “skip” was rolling I could get out quite far with my little 50W linear. One time supposedly all the way to California from Georgia. I say supposedly as not everyone tells the truth, so who knows.
It was a little odd cause you never knew how far you could get out, you may get out fine to 500 miles and talk fine, but not be able to do 50 miles, and get great modulation now, then ten minutes from now, get nothing at all.

Also I think maybe that now we are in a period of higher than normal sun spot activity and that has a tendency to shut down long range commo, I assume due to noise? I don’t know about sun spot activity, I think I read that somewhere though.
It runs in a cycle, about ten years?

It is common to be able to communicate with someone 500 miles away but not someone 50 miles away, depending on the frequency and other variables. The guy 50 miles away might be in your "skip zone", the guy 500 miles away catching your signal after it bounced off the ionosphere.

As for sunspots, we are actually fairly low and headed into a period of even fewer in the 11 year cycle. This will result in reduced long distance transmission, affecting higher frequencies more than lower frequencies. The recent solar flares also tend to disrupt HF communication for periods of hours.

Chip

[ka4wja]

A64,

1) As you've already found out LMR-400 cable is the wrong cable to use on-board (even for VHF)....LMR-400UF is okay for VHF use, but is still an over-kill in our VHF-FM systems!! LMR-400 uses a solid (stiff) copper-clad aluminum center-conductor!! (yikes! just what everyone wants on-board in the sea air, huh?? copper clad to aluminum and it's a solid conductor that once bent too far the copper-clading is cracked, and then we all know what will happen in matter of time....bottom line is LMR-400 is the worst possible cable for use on-board....LMR-400UF is "acceptable" for use in some applications, but is serious over-kill for HF!!)


I like RG-214 (a lot!) and RG-213, and they're great choices for you, primarily because of their size/strength/physical integrity, not because of any minor (~ 1/10 of a db) reduction in loss!! FYI, RG-8x (assuming a good quality brand) or RG-58 will work fine for HF freqs, even for lengths of 100' or more, it's just the mechanical strength of the larger size cables make them better suited to our on-board application!

{Please note that if you haven't experience installing connectors on RG-214, please use other cable or hire a professional to install them....the silver-plated shield (or "tinned-copper" in some versions) is nice to solder to, but the fact that there are TWO braids makes it a pain-in-the-butt the first time out!! Crimp connectors (good ones) are a good-send here, but the crimp tool/die is pricey, hence why I wrote "hire a pro"....Or just buy a pre-made cable assembly... }



2) Also, as you've already found the AT-140's internal switch should be left in normal mode, as the only use for this is if you were using a non-Icom radio and had a "KEY" voltage greater than 8vdc...





3) As for GTO-15 running next to other wires??

As Dan has mentioned at right angles, usually no problem at all....even at closer distances of an inch or two, you're usually fine at right angles....but, if running parallel for any significant distance (more than 6"), then yes you may need to add ferrites onto the other wires (again not the GTO-15), but depending on what those other wires are, sometimes even that won't be necessary.... (although, if they are ethernet, USB, NMEA, etc. then ferrites will probably be an absolute! and if they're from your refrigeration, or something else that produces receive RFI, then ferrites on them will absolutely be necessary!!)

Now, as for the GTO-15 running along the backstay (below the insulator), assuming you do not have a ground wire on the chainplate, there is NO issue with this!! Despite all the old-school warnings that some of your signal will couple to the backstay (some of it will), this is not a problem!! Yes, you can still find some that will rig "stand-offs" to hold the GTO-15 a couple inches away from the stay, the facts are (backed-up with some real-world tests at the US Naval Academy) that there is no measurable difference in either transmit performance, nor receive signals....(now, if this was a steel hull, or you had a direct sea-water ground connection on the chainplate and hence the stay below the insulator, then yes, some of your transmit energy would be coupled to "ground", and hence use of "stand-offs" would be recommended....but, other than that, they are unnecessary!)




4) As for the use of wide copper strapping (please do not use foil!) for connecting the tuner to the sea-water....this is because most use the sea-water as the other half of the antenna / the Antenna Ground / RF ground (where the antenna return currents travel), and we want as low impedance connection to this (sea-water) as possible....

If, on the other hand, you desired to use an artificial ground / counterpoise, then of course simple wire radials work just fine...

I do not have enough time to explain all the details here, but I have done so in the past, right here at Cruiser's Forum (have a look)...
There are arguments to be made to place the tuner as close to the backstay as possible...BUT...

But, unfortunately in our real-world, on-board our boats, we also need to get a decent Antenna Ground! And, that usually means placing the tuner as close to a sea-water connection as possible...

Opps....what if these two places are not the same??
You compromise, of course!!

And, then don't forget they are sailboats, and we use 'em for a lot more than just radio shacks and antenna mounts....so, sometimes the tuner isn't in the "perfect" location....but, you simply make it work as best you can!





5) Finally, as for long-range comms via HF radio....I do it all the time!!
It's the mid-range (100 - 300 miles) that's tough sometimes!

I regularly hear Australian Maritime Weather on 12.362mhz and 12.365mhz in afternoons and even on 8.176mhz late in the day and at night....and those transmitters are approx 9000 and 10,500 miles from me in Florida...

And, every time I step on-board, within one minute of turning on the radio, I can find and talk to stations (primarily on the ham bands, but also WLO and NMN) from hundreds to thousands of miles away...every time....(excluding the hour or two that a solar flare or CME might cause a radio black-out)

It's all about knowing how....you will need to learn HF radiowave propagation, just like you learned to sail, navigate, anchor your boat, trim the sails, flush the head, etc. etc...nobody is born with this knowledge and expertise, you learn it!



I don't want to sound immodest, but if you watch the videos in their entirety, you will learn a lot!! (and, if you watch the videos in order, in these playlists, you'll gain an understanding of this which will put you ahead of 95% of your fellow cruisers)

Maritime HF Comms
https://www.youtube.com/playlist?lis...ZDo_Jk3NB_Bt1y


Icom M-802 Instruction Videos
https://www.youtube.com/playlist?lis...rC-8QKVyMb4tVr


HF-DSC Comms
https://www.youtube.com/playlist?lis...ga2zYuPozhUXZX


Offshore Weather
https://www.youtube.com/playlist?lis...zdjTJjHlChruyY




Hope this helps.
John

P.S. Sorry, I missed this earlier....I'm taking care of some family matters, so am not on Cruiser's Forum much...

[a64pilot]

Wow, don’t know where to start.
I used 2” wide strap, I believe .030 thick, it’s tough to bend, it was the thickest Georgia Copper had, I wanted resistance to corrosion. I was able to keep the total length down to about 4 or 5 feet. I have about 20’ left over to give away I guess. It’s connected to a large Dynaplate I got from Frankly.
I won’t use the RG214, I have at least 50’ of it, but it’s just too easy to order RG8 premade, distance between transmitter and tuner is 23’, so I ordered one 25’.

I have done some looking and I can run the GTO 15 90 degrees to the wiring and keep it down to 8 feet or so, just don’t run it along the aft stay, it will come straight up out of the hull to the aft aft stay.
I just bought a clamp made to connect two 1ga wires together and drilled and tapped the head of it to accept a 10/32 screw and will use it to connect the GTO 15 wire. Gary Jensen at Dockside radio suggested this.

I’m about half way through your 802 videos, I have bandwidth issue now and am struggling but I’ll get to watch all of them if I have to go to a coffee shop.