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Old 21-03-2017, 18:39   #16
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Re: Hoisting a Ham Band antenna next to the insulated backstay

Thank you, Knockabout. . A long marine whip connected to the autotuner would be a good strategy. Regarding counterpoises, I need to research more. Your words were clearly written, but I am quite ignorant on the subject. l only understood vaguely about half of what you explained regarding counterpoises for two transceivers. Toddster8, the high price of the SCS modems is obviously due to a market monopoly. I wonder whether Winmore would be a practical alternative. Or, are we stuck with Pactor?
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Old 22-03-2017, 03:10   #17
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Re: Hoisting a Ham Band antenna next to the insulated backstay

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. . . Toddster8, the high price of the SCS modems is obviously due to a market monopoly. I wonder whether Winmore would be a practical alternative. Or, are we stuck with Pactor?
There's a lot of technology in a Pactor modem, and the market is very small, so a lot of development costs have to be spread over a fairly small number of units. I don't actually think they are so expensive, for what they are.

You can do WinLink with Winmor, with a fair number of stations able to connect by Winmor, but for SailMail I think you must have Pactor.

Pactor III, and especially, Pactor IV is faster and gives more robust connections, than Winmor.

Any Pactor II modem can be upgraded to Pactor III in firmware (and probably most of them already have the upgrade). On a budget, a used Pactor IIusb (say), is a really good solution and not really expensive at all. It's half the speed of Pactor IV and nearly as reliable connections. It's as fast as you can get (mostly) with Winlink anyway, because Pactor IV speeds are not yet allowed on amateur bands (theoretically).


Concerning the radio installation:

Installing one HF radio in a sailboat, especially if you buy a whip antenna for it, has got to be more or less equivalent in cost to the price of the radio itself.

So wouldn't it make sense to sell both radios and buy a single radio suitable for both ham and marine use? Then you only have to do one installation, and you eliminate all the conflicts between the antennas.

I use an Icom M-802 and really don't want for anything else for ham HF. It doesn't have all the controls a ham transceiver has, but on the other hand the M-802 has superior performance in many respects to most moderate price ham transceivers. The M-802 is specifically designed to be connected to a Pactor modem and is really convenient for digital modes. And it has DSC, which is a whole other topic . . .
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Old 22-03-2017, 05:02   #18
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Re: Hoisting a Ham Band antenna next to the insulated backstay

You are not stuck with Pactor. Do a search on "winmor". This is a sound-card substitute for Pactor, although it can only be used on the ham bands (but that does not appear to be a problem for you). Winmor is a little bit slower than the latest Pactor modems, but quite adequate for sending and receiving text e-mails. Best of all, it costs absolutely NOTHING!
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Old 22-03-2017, 05:30   #19
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Re: Hoisting a Ham Band antenna next to the insulated backstay

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You are not stuck with Pactor. Do a search on "winmor". This is a sound-card substitute for Pactor, although it can only be used on the ham bands (but that does not appear to be a problem for you). Winmor is a little bit slower than the latest Pactor modems, but quite adequate for sending and receiving text e-mails. Best of all, it costs absolutely NOTHING!
I use winlink, works fine so far in Europe. Well worth splashing out on a signalink usb soundcard, makes digital modes so much easier. ->Tigertronics Home Page
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Old 22-03-2017, 05:35   #20
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Re: Hoisting a Ham Band antenna next to the insulated backstay

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You are not stuck with Pactor. Do a search on "winmor". This is a sound-card substitute for Pactor, although it can only be used on the ham bands (but that does not appear to be a problem for you). Winmor is a little bit slower than the latest Pactor modems, but quite adequate for sending and receiving text e-mails. Best of all, it costs absolutely NOTHING!
The theoretical maximum throughput of Winmor is half that of Pactor III, which might be enough. Pactor IV is 1.5x to 3x faster than Pactor III, so 3x to 6x faster than Winmor.

But theoretical maximum throughput is not really an accurate reflection of real life, especially in remote areas with weak signals.

As one ham put it:

"People often ask me - Why buy an SCS modem when we now have Winmor? Well, I have both capabilities installed in the shack here - And Winmor does not even come CLOSE when it comes to weak signal performance.

To be fair to the Winmor development team, they have created the best that is humanly possible given the limitations of a sound card and Windows unpredictable timing, which makes highly synchronous ARQ (like the SCS-PTCII does) impossible. Synchronous ARQ can only be done with dedicated TNC [Dockhead: this means "Terminal Node Controller" -- ham-speak for a modem] hardware (or by running a real-time operating system on your PC). The weak spot in Winmor is therefore the fact that the receiving station needs to re-synchronize on every individually received data packet, which is a severe penalty in the required S/N ratio for the system to function in very poor band conditions.

"But I'm getting of track here. SCS-PTCII modems - the best there is. No question about it. I also have professional experience with military Stanag HF radio modems (the Harris modems), and I tell you - those Germans put our American engineers to shame. There is nothing better in the market today for HF digital communication within a smaller than 2.5 kHz bandwidth than the SCS modems. Plain and simple.

No, I have NO ties to the company whasoever.... All I am is a very satisfied customer."


SCS PTC-II Product Reviews


So you really can't say, that the difference between Winmor and Pactor is that Winmor is "a little slower". Winmor is fun to play around with, but if you actually need to be able to rely on getting messages passed back and forth, as opposed to playing around with it, then Pactor is worth its weight in gold.


It should be said that even better than any of this, if your messages are short and text-only, is satellite messaging using DeLorme or Yellow Brick. Cheap, simple to use, reliable.
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Old 22-03-2017, 05:58   #21
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Re: Hoisting a Ham Band antenna next to the insulated backstay

Okay, it is more than a little slower. Still, I have been using Winmor to send and receive e-mails and have never had any problem at all. Of course, I must admit that I'm not trying to do business this way, or anything like that. I receive grib files, and I send short e-mails along the lines of "AOK, 26.779 -77.337"

One time, when my wife's father was in the hospital, our daughter sent us an e-mail that said "Call ASAP". These kinds of things have always gotten through promptly and without any problems.

Honestly, I sail to get away from e-mails and business, so I really don't want any more elaborate communications than this.
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Old 22-03-2017, 06:01   #22
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Re: Hoisting a Ham Band antenna next to the insulated backstay

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Originally Posted by denverd0n View Post
Okay, it is more than a little slower. Still, I have been using Winmor to send and receive e-mails and have never had any problem at all. Of course, I must admit that I'm not trying to do business this way, or anything like that. I receive grib files, and I send short e-mails along the lines of "AOK, 26.779 -77.337"

One time, when my wife's father was in the hospital, our daughter sent us an e-mail that said "Call ASAP". These kinds of things have always gotten through promptly and without any problems.

Honestly, I sail to get away from e-mails and business, so I really don't want any more elaborate communications than this.
If it works for you, then that's good enough for you

Of course it depends a lot on where you are.
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Old 22-03-2017, 06:48   #23
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Re: Hoisting a Ham Band antenna next to the insulated backstay

OK, you did ask for it!
My system uses multiple rigs and multiple antennas. This requires an engaged operator.
All HF Rigs are routed to an AlphaDelta Coax Switch
All Antennas are Routed to an AlphaDelta Coax Switch
Switches are connected so that any rig can go to any antenna
Wire antennas are connected to UnUn Transformers from Balun Designs designed to permit coax feeds OR connected directly to a tuner (I use an SGC 230). A BIG knife switch serves to choose which input to wire (Tuner or Coax to Balun) is chosen.

My DEFAULT position is to have a marine radio direct to the SGC230 to the wire. Anyone can use this for calls and emergencies; it takes 3 minutes to convert to a multi tranceiver Ham System (756PII and FT100D) using an SGC 500 Amp and a Palstar 1K Tuner. It's a good system for an active ham but not for a boater who just wants a radio.

Bottom line, make the AT120 work with both rigs, use one wire, and life will be good. Either radio can use the AT120 with simple mods.
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Old 24-03-2017, 02:49   #24
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Re: Hoisting a Ham Band antenna next to the insulated backstay

I would really suggest using Bill Trayfors's advice.
The only extra investment would be a tuner like the SGC230 and a coaxial switch, and used both transceivers (Marine SSB and HAM SSB) and the one insulated backstay antenna.
Look for a switch that puts the unused connector to mass. That would however not be enough to protect the other transceiver if switched on, in my opinion.
You will need the precaution and disciplin to switch off the unused transceiver.

Pactor: WINMOR now has a software decoder that works qute well with the Winlink system. I use it and requesting and loading gribfiles, and simple emails work well.

Jan
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Old 28-03-2017, 09:02   #25
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Re: Hoisting a Ham Band antenna next to the insulated backstay

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...the two antennas would be close to each other, especially at the upper end, maybe one foot apart. Will this setup work? Are...there any disadvantages?
Any antenna is affected by any nearby conductor. The degree to which a nearby conductor affects an antenna is related to the distance separating them and the resonance of the non-antenna conductor at the operating frequency of the antenna. The closer the physical distance and the closer the resonance, the greater the effect of a nearby conductor on an antenna.

In the case of two antennas that are only 1-foot apart, there will be considerable influence even if the second antenna is not resonant at the operating frequency of the first antenna.

A general rule for any antenna is to be installed in the clear, that is, away from as many other conductors are possible. Putting two similar antennas only 1-foot apart is perhaps the exact opposite of the goal for antenna installation, as the two antennas will interact.

The advice you received to use one antenna and connect it to different tuning units as necessary is good advice. If one tuning unit can work with the antenna over the range of frequencies needed for both radio transmitters, then use that approach.
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