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Old 18-05-2009, 11:01   #1
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ICOM 802

I have an ICOM M802 with an AT140 tuner, a Pactor IIusb and a Gam/McKim backstay antenna. We have 2 Dynaplates connected by 2" copper strip to both the tranceiver and the tuner.
My problem is voice transmission. When I use the Pactor, connection is usually efficient and and my ammeter shows a draw of 22 - 25 amps. On voice I am unable to connect to stations 30 miles away and the ammeter shows barely 5-7 amps. a DSC self test pulls about 15 amps on transmission.
I am at a loss - can anyone help.
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Old 18-05-2009, 11:12   #2
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The average power draw on ssb should be low compared with Pactor or other digital transmission as the duty cycle is much lower except on voice peaks which you'd never notice on a dampened ammeter - you'd need a peak reading ammeter to see the actual instantaneous draw on ssb.
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Old 18-05-2009, 12:26   #3
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As far as not being able to communicate on voice, read HF Radio
for a discussion on optimum frequencies.

I'm not a big fan of the Gam antenna, as its too close to the the backstay which will attenuate its signal.
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Old 18-05-2009, 13:22   #4
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Ditto on S/V Illusion's post. The 5-7 average amps is normal on voice for the 802. It is somewhat weak in my opinion as compared to other rigs including Icom's such as the M710. The 802 is advertised as having DSP compression providing more average power when in fact this feature is not enabled. Trying to communicate at 30 miles on HF may be very difficult as this would be via ground wave which doesn't get out too far depending on frequency. HF is normally used to communicate long distances via sky wave from around 100-200 miles to thousands of miles depending on frequency and propagation conditions.

Eric
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Old 18-05-2009, 21:37   #5
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HF Comms in the Med

Hugh,
s/v Illusion, Don and Eric have given some good input.....and here's some more.....
(I'll be as non-technical as I can.....but, I REALLY wish everyone had an RF watt meter / swr meter on board, since it would make troubleshooting easier, as well as making sure your rig continues to work fine for years.....)

1) To expand on Eric's point on a 30 mile contact on HF....

a) it depends on what frequency you tried......2mhz and 4mhz are best for this distance....and you should be able to connect 30 miles on 2mhz on ground wave.....and 4mhz is possible.....
Most times you'll not even hear others on 7mhz/8mhz, and above, at distances of 25 - 30 miles.....(there's a LOT more to all of this, but just the highlights for now....)
As you can see, Ground Wave comms on HF is a limited mode.....

b) Try to connect with stations that are 400 - 1000 miles away, on 4 - 12 mhz......and you'll probably be successful.....

You should also be able to work some sky-wave comms on 4mhz, 6mhz and 8mhz during the Daytime, at distances to 50-100 miles out to 300 - 1000 miles....depending on exactly what band/freq, time of day, and sunspot activity.....

(I'd try a daytime 8mhz contact at ~~ 200 to 500 miles, just as a test example...)

c) Also you may have had noise sources, especially at the other boat's location, which will have a significant effect on your ability to contact them....but the PACTOR stations (sailmail and/or winlink) you contacted will typically make every effort to keep their noise level low.....
So, while contact with them on PACTOR means that your set-up IS working, it does not tell the whole story.....


2) 5 - 7 amps of average current draw, on SSB with normal speech....is very normal.......

a) Although some M802's did have an "audio clipping" problem, which Icom does have a fix for, I do not know the exact S/N that the "fix" was intiated at, at the factory.....
(Although Icom specifically mention it was noticeable when swr was >1.6:1, there are users that experienced this trouble with lower / escellent swr readings......leading me to assume that the M802 without this mod, is very susceptible to small troubles, even if a meter cannot respond quickly enough to show a problem....so, even if your swr match is good, that doesn't necessarily mean an M802 without the "mod" is okay....)
Assuming you have a US/North American M802, these following s/n should be useful.......but if it is an EU model, I don't know if the s/n will track correctly......
But, what I DO know is that my second M802, s/n 0106996, did NOT come from the factory with this "mod" (Although I sent it in to Icom service in early 2007 and they did it for free).....
And, further, Eric noted earlier that an M802 s/n 0108290, DID come from the factory with this mod already installed.....

So, if your M802 s/n is lower than 106996, it may need this mod.....and if it is higher than 108290, then it does not need this mod......

See Ocom's website for some details....
Icom America - Knowledge Base Article 732B232987


b) Furthermore, although it is in the manual, connection of a copper strap (or any grounding wire/strap) to the M802 transceiver itself is typically NOT done, since it can cause RF ground loops and hence RFI, RF feedback, etc. which can impact your output......

I'd suggest you disconnect the copper strap at the M802 transceiver ground terminal and see if you get any improvements.....


3) As for the GAM antenna......
It does work, but I too am NOT a fan of it.......

4) Your current draw when making a DSC call (15 amps), compared to a PACTOR call (22 - 25 amps) is odd.....
{DSC is 100-baud SITOR...}
It doesn't necessarily mean that there is a problem......But, it does make me wonder what your power output actually is.....and on what band/freq did you do all of these tests????

If you, press the "MODE" button until "FSK" is displayed, and them press the PTT button, you'll be transmitting a solid carrier......
Depending on what power setting you have selected (low, med, hi) you should have 20w, 60, and 125-150w output, with 2-3 elements lit on the display for 20w, 4-5 elements lit for 60w, and all elements lit for 125-150w......

Measure your current draw, at each power setting, when doing these quick tests.....

USA/North American M802's do not have a calibrated scale on this meter, but I've heard that AU and/or EU version M802's have a sacle of some sort on the display......but whatever the case, the display should show the approx. number of elements lit up, at those different power levels.....

Use these current draw numbers to compare with your previously measured current draw numbers....(using the SAME freq/bands).....and you should be able to draw some conclusions on whether your DSC transmitted power output is correct....


5) Since I do not know where in the Med you are, I cannot make eaxct reommendations, but here's some general ones....

a) Olympia Radio, in Greece still stands by on a few HF Hi-Seas Voice ITU channels, and they have an automated "voice beacon" on their 8mhz transmit freq (female voice) that is easily heard here 6000 miles away on 8.776 mhz......

You should be able to contact them from anywhere in the Med, with no trouble.....
Just use the proper freq for your distance and time of day.....
ITU Channel 603, your transmit = 6.206mhz... your rec = 6.507mhz
ITU Channel 806, 8.210mhz / 8.734mhz
ITU Channel 820, 8.252mhz / 8.776mhz
ITU Channle 1232, 12.323mhz / 13.170mhz
ITU Channel 1640, 16.477mhz / 17.359mhz
ITU Channel 2217, 22.048mhz / 22.744mhz




b) There still are maritime coast stations, in the Med, that keep watch on MF / ~ 2 mhz freq as well......and you could try a contact with one local to you as well....



6) If after all of the above doesn't seem to get you any contacts, please let us know....and, you may wish to post an inqury on the Seven Seas Cruising Assoc discussion boards, since there is a large wealth of knowledge there also....
www.ssca.org

Or, you may find the UK/EU centric OCC notice board to be hrlpful as well.....

I do hope I helped.....

John
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Old 18-05-2009, 21:44   #6
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Eastern Med Cruising Nets???

Sorry, one thing I forgot was a few times/freq for Med HF Cruising nets....
I'm not sure how up-to-date this info is....but have a listen and see...

In Eastern Med, Greece/Turkey:
Daily at 0500z, on 6.224mhz (6A)
Daily at 0645z, on 12.252mhz (12A)

Agean Sea:
Daily at 0800 - 0900 Local Time, on 4.417mhz

Again, not sure how up-to-date this info is....but thought I'd pass it on in any case....

John
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Old 19-05-2009, 05:42   #7
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Thanks for all the ideas so far.
I have found the Sn is 0106367, which seems to be a failry early model although bought in Gibraltar in 2009. There is nothing there to show it is a European model and indeed the M801E is ICOM's European offering. I think I will have to get the rig properly tested and will press ahead in that direction while I try making better use of propagation info.
Any further comments most welcome.
Hugh
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Old 19-05-2009, 10:17   #8
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Thanks

I have a lot of info now and have also found the Sn to be 0106367 so may be affected by the clipping problem. I will try to find someone who can test my rig and see exactly where if anywhere there is a problem.
Thanks once again for the advice and I will be continuing with contacting local and more distance stations over the next day or two.
This is a great forum
Hugh
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