SSB power issue on 6,4,2 megs

[mdsilvers]

Hello everyone. I am having a challenge troubleshooting a power issue in transmit for 6,4,2 megs.

I have the icom 802 with dynaplate and whip antenna on my catamaran. I am booming on 8megs. Today I moved to 4 megs to avoid a skip and realized I have virtually no power.

If I whistle in the MIKE on 2,4,6 I get 1-2 bars and am very faint 1/5 on signal compared to other boats. If I do the same whistle test on 8 megs I get full bars.

So, not sure what I need to check. All connections are good and I consistently have one of the stronger signals on 8megs so not sure what I need to check.

Thx in advance.


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[smac999]

do you have a tuner as well?

[mdsilvers]

Yes. I do have the tuner. After dialing the frequency I even hit the tune button just in case. I can hear the tuner click.


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[RaymondR]

The fact that you get a better result on the higher frequency might indicate a problem with either the tuner or the antenna rather than the tranceiver.

[mdsilvers]

Thx. I will do some more checking on the tuner. Any tips on the best way to isolate the issue? I can hear people fine receiving on the lower frequencies. We r in Vanuatu so I am needing to isolate the issue myself as there are not any good options for a technician to check out here.


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[RaymondR]

When I worked on offshore drilling rigs in the days when they still had radio operators they used to tape a neon indicator on the antenna feed line to be able to check at a glance whether or not and how well the transmitter was feeding power to the antenna. Other than a field strength meter I don't know of any other way of checking whether or not the antenna is radiating properly.

[robert sailor]

You might also consider your counterpoise system as a poor system tends to work well on high frequencies but lousy on low frequencies.

[Rhapsody-NS27]

First of all... did you get full power out on the other bands in the past? How long have you had this setup?


My first thought was maybe the antenna isn't made for the bands you're not getting out on. If the antenna isn't, then your signal output will be attenuated so you wouldn't be putting much out. Do you have an SWR meter to measure power reflected back to the radio?


If it was working before, then check all your connections. Possible wiring broke somewhere along the way. Also, like suggested above, check the counterpoise system.


Lastly, is your radio included in the boats grounding system?

[knockabout]

are all the frequencies in your radio/has it been modified for marine or single band use

[cal20dennis]

Must be tuner problem...clean all connections, then tune and listen for strength of signal from Greenich Mean Time stations. If strong audio (during hours of good propagation), then possible problem with transmitter. On only selected frequencies? (Seems unlikely that your radio has a transmitter fault on some frequencies but ok on others)
Gotta be a tuner/ antenna problem !
Good luck, 73's from KF6JKM

[svlamorocha]

Did it work fine in 2 and 4 Mhz before? If the problem is new, I suggest you check the soldered connection (covered with PVC tape I think) of the thin wire that forms the core of the whip. I am talking about the soldered connection on the outside surface of the whip and just above the fitting that attaches the whio to the hull.

A bad connection there could perform differently depending on frequency.
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[svlamorocha]

Also check that that the connections between Dynaplate and tuner are good. Unfortunately the wavelength for 2 MHz and 4 MHz is a bit too much to use 1/4 wave radials. Still, if you want to check if the problem is in the ground side you can add a 20m wire (for 4 Mhz) wire and tow it behind you as John T.... If that changes the tuning of the tuner then your Dynaplate or its connections may be the issue.

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[Scott Berg]

All good suggestions but to really diagnose this:

Get a dummy load and swr/power meter and do direct tests on the radio without the tuner.

That will tell you where the problem is.
If you get 150 watts out of the radio using FSK it's in the tuner or antenna.
Move the dummy load to the tuner out and repeat...



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[ka4wja]

Mark,
While it has been 4 days since you asked for help, I just came and saw your questions!
And, as I start typing this it is almost 6am local time in Vanuatu, so I hope to catch you early in your day, BEFORE you go out to try and find any equipment or assistance, because ALL you need to trouble shoot this problem you probably already have (the M-802, your own eyes and ears, and a dc volt meter, or a digital multimeter).
{yes, a dummy load and an external power/swr meter would be nice, but actually you CAN do this without them!}

There is plenty of troubleshooting info available right here, and I will endeavor to search for the pertinent postings and add them here to this thread, so you can figure all of this out...

Before I go and look for all the details....
My initial thoughts are:
a) Tuner issue/failure...
b) No DC power getting to tuner...
c) Whip antenna connection..
d) Copper strapping connections, from tuner to Dynaplate...

Although the "tuner issue" could be an internal failure, that is actually quite rare....and all of these first 4 possibilities are usually caused by bad connections (or a blown 5-amp fuse inside the M-802), and all can be easily fixed on-board by most laypersons in short order....we just need to give you some direction to find the trouble!!


More later!

John

[ka4wja]

Mark,
While it has been 4 days since you asked for help, I just came and saw your questions!
And, as I start typing the earlier post, it was almost 6am local time in Vanuatu, so I hoped to catch you early in your day, BEFORE you go out to try and find any equipment or assistance, because ALL you need to trouble shoot this problem you probably already have (the M-802, your own eyes and ears, and a dc volt meter, or a digital multimeter).
{yes, a dummy load and an external power/swr meter would be nice, but actually you CAN do this without them!}

There is plenty of troubleshooting info available right here, and I will endeavor to search for the pertinent postings and add them here to this thread, so you can figure all of this out...


BTW, I am assuming that your system DID previously work fine on 4mhz and 6mhz???
If this is not the case, well......well, we will have a LOT of work to do....troubleshooting thru an on-line forum, from the other side of the planet isn't the easiest!


And, you've made no mention of your reception of others on these different frequencies???
So, I'm going to assume that your reception is excellent on all bands / frequencies...if not...well, we've got a lot more to think about!

Further, you haven't written of your technical abilities, nor electronics / communications experience....
So, I'm going to assume you're like most cruisers....a layperson, with lots of well-intended but erroneous radio info, shoved at you!!



BTW, as I start to write this it's about 6:30am local in Vanuatu...
And, as I finish it's just after 8am local time for you in Vanuatu!!!
So, hopefully you'll see this and do the tests...

Before I go with all the details, my original thoughts are still:
a) No DC power getting to tuner...
b) Tuner issue/failure...
c) Whip antenna connection..
d) Copper strapping connections, from tuner to Dynaplate...

Although the "tuner issue" could be an internal failure, that is actually quite rare....and all of these first 4 possibilities are usually caused by bad connections (or a blown 5-amp fuse inside the M-802), and all can be easily fixed on-board by most laypersons in short order....we just need to give you some direction to find the trouble!!



Okay, here comes some help...

1) First off, assuming by now that you've checked the whip antenna connection and your copper strapping connections, and found them good and/or cleaning made no difference, etc....
We need to proceed further!


2) You made no mention of anything else attached to the M-802 (such as a PACTOR modem, audio cable to a laptop, etc.), but if there is anything, please disconnect it all first, before going any further!!


3) A VERY simple and easy test to see if the M-802's transmitter PA (Power Amp)is performing properly is to eliminate the possibility of you having a "clipping issue" and/or an RF Feedback issue...(and also listening to see if the M-802 is switching in the proper output filtering, which would be the only major internal issue that could cause the problem you've described)

Since the "clipping issue" only manifested itself on older M-802's (those with serial numbers below 0108261 ), only in SSB Voice mode, and since 90% of RF feedback issues effecting the transmitter's power output only manifest in Voice modes....checking the M-802's output in FSK mode is a good way to start...(not to mention it is a lot more professional than a whistle)

a) turn on radio..(and make sure you are in "hi-power" mode by pressing the "F" button and then the number "9" button and then the "ENT" button)

b) select an 8mhz channel that you normally use, verify that nobody is using that channel at that time, and then turn your volume down...

c) press the Tune button, and verify that on the upper left of the display "TUNE" blinks while the tuner is tuning, and that "TUNE" stays showing after the tuner has completed its tuning. (if this is not happening, try another channel, like a 12mhz or 16mhz channel, and try again....if no joy, then we may have found a major part of your problem)

d) press the "mode" button (immediately below the "tune" button), press this button a few times until you see "FSK" (or "F1B") on the top center of the display....you are now in FSK mode, and simply pressing the microphone's Push-To-Talk button on the side of the mic, will send out a single unmodulated carrier at full power...

e) press the microphone's Push-To-Talk button on the side of the mic, and send out a single unmodulated carrier, and observe the M-802's power output display...
You should see all 8 segments illuminated ("full bars"), and you should also still see "TUNE" showing in the upper left of the display...


f) now, with the volume still down all the way, listen with your ears near to the M-802's main unit (or have some else listen for you), while you turn the channel knob to select a 4mhz channel..select a 4mhz channel that you wish to use and verify that you heard a few clicks from the M-802's main unit when you changed channels, from 8mhz to 6mhz and 4mhz, etc. (this means the M-802 is switching in the correct output filters...but you may not hear them too well, so this is only a secondary test, if we find a problem in a minute)
Select a 4mhz channel that you wish to use and now turn up the volume to verify that nobody is using this channel

g) now perform these steps "c", "d", and "e" again...

--- If you heard the M-802's main unit make a couple clicks when you changed channels (in step "f"), AND you still see only 1 - 2 bars of transmit signal in FSK mode, you can be fairly certain you do NOT have anything major wrong with the M-802, and the problem lies with:
-- no voltage to the tuner,
-- the tuner wiring,
-- antenna wiring,
-- or the tuner itself...
And, you should also see the upper left side of the display either blink "SWR" or simply show "THRU" (instead of showing "TUNE")...

{The M-802 does have a basic transmitter power meter and SWR indicator...

It shows its transmitter power output in 8 segments, of approx. 15 - 20 watts each, and by using a constant carrier in FSK Mode, you can easily check your transmitter's power output in all three power modes "low-power" (~ 20 watts) should have one to two segments, "mid-power" (~ 60 watts) should show 4 segments, and "hi-power" (~ 140-150 watts) should show all segments....all assuming the M-802 is transmitting into a tuned antenna (or dummy load)....

If you get the "proper" output in "low" and/or "mid", but not in "hi", you likely have a slight antenna / tuner mismatch and will see "SWR" in the upper left of the display, indicating an SWR of approx. 2:1...

If you get proper output only in "low", you will probably see "THRU" in the upper left of the display, and you will have an SWR of greater than 2.5:1 to 3:1....which would most likely be caused by the tuner not working at all (no 12vdc power to it, no control telling it to work, or a tuner failure), or possibly no antenna connected at all
(in your case we know the antenna is connected to some extent, so this would indicate no tuner dc power, the tuner wiring, or tuner itself...) }

~~~~

Please take note that doing all of the above will take you no more than 5 minutes and you need NO special equipment at all!!
(also note that other than mentioning that you should check your copper strapping, and Dynaplate connections, I've made no big issue out of this...this is because as long as the connections are clean and solid, there is nothing to do or worry about....you have an excellent antenna / rf ground, and since you probably just sailed across the Pacific, I doubt there is much marine growth on the Dynaplate, but having a quick look and give it a scrub if needed is fine!)

~~~~
{Also, please note that with 4 - 5 feet of GTO-15 wire going to a standard 23' whip antenna, you have an approx. 1/4-wave end-fed antenna on 8.2mhz!!
Which, with an excellent ground system, would generally show a 1.5:1 SWR without any tuner working at all...and with a lossy ground system, probably an even better SWR...
So, having a good signal on 8mhz but not on any other band (at least not on any of the lower bands), would be quite common if the tuner was no longer operating for any number of reasons!!}
~~~~



4) Now to move further and determine where the problem lies...
-- no voltage to the tuner,
-- the tuner wiring,
-- antenna wiring,
-- or the tuner itself...
You can do some further testing on other bands/channels, such as 12mhz, 16mhz, 18mhz, 22mhz, 25mhz, etc....but probably quicker to just will skip them for now, and get out a dc volt meter!!!

You will need to measure voltage on the back of the M-802's Main Unit, on the tuner control socket...

These are VERY small and delicate pins, and you CANNOT short them out!!
So, if you are NOT certain you can do this, please do NOT go any further until you can find someone who IS capable...
(although chances are the worst that would happen is that you blow an internal fuse inside the M-802, there is a possibility that something else could happen, and since you are in Vanuatu, without any marine SSB technicians nearby, I want to impress caution here!!!)

If you look at the M-802 manual, page 61, and on page 3 of the AT-140 manual (you do have them, yes??), you'll see the tuner control wiring..

Pin #4 is ground, the black wire...

Pin #3 is your DC positive, the red wire...

Pin #2 is the "Start", the white wire...

Pin #1 is the "Key", the green wire...

BEFORE going any further, verify you have these wires attached and all is clean and tight!!!
(and, check the tuning and output on both 8mhz and 4mhz, again, before going any further...)



My caution is telling me to have you do all the above tests AND then report back here, BEFORE you go any further....but, if you are sure of your abilities to measure these small pins without shorting anything out, then go ahead...

--- If you still have no tuning and low output on 4mhz, FIRST turn OFF the radio....
--- Then, carefully pull the tuner control wire plug straight out...
This will allow you to check the voltage on pin #3 and #4...

--- Set your volt meter to read DC Volts on a low scale (15 - 30 volts or so)..


--- Carefully attach your negative lead from your voltmeter to Pin #4...
Do NOT allow this to touch any other pins!

--- Carefully attach your positive lead from your voltmeter to Pin #3...
Do NOT allow this to touch any other pins!

If you need to hold these leads in place, while someone else turns the radio On, that is okay, just make sure you are touching only pins 3 and 4...
Then turn the radio on...
You should see 12vdc to 14vdc on the meter....you will see whatever voltage you have at the radio (what your 12vdc battery system is showing)..

If you do NOT have this voltage, then the problem is a pretty easy fix!!
You probably have blown a 5-amp fuse inside the M-802's main unit....and it will take you about 15 - 20 minutes to open up the radio and replace the fuse....
But, be aware that fuses usually blow because of a reason....so you might need to go further to find the reason the fuse blew!!



If you DO have this voltage, then we need to go further....
Before we delve into how to measure the "start" voltage, which isn't as easy as it seems as you'll need the tuner connected....lets see where your tuner is...and if we can measure the voltages at the tuner end of the tuner control cable...

This is a common failure point....as the AT-140 comes with a short pigtail and the connection there can be an issue...
{Also note that this is the location where you would install "ferrites" on the tuner wires (and a line isolator in the coax line), to prevent RFI....and since these ferrites add some weight and movement along an ocean passage gives them some momentum, this can be a place where a connection problem can be common!!!}



So, if you DO have 12vdc to 14vdc on pins #3 and #4 back at the M-802....please do this same procedure of testing the voltage on pins #3 and #4, back at the tuner end of the tuner control cable....

If no joy....then you've most likely found your problem!!
If you DO have power there....well then we will need to look at the "Start" voltages, etc...
And, some of my further troubleshooting recommendations will be based on what YOUR results of all of these above tests are...
SO...

So, you will need to do all of these tests and report your findings back!!



Again, please take note that all the above can be done in less time than it takes to read all of this!
And, you do not need any specialized test equipment at all...(yes, if you had a dummy load, a couple long coax jumpers, and a external power/SWR meter, things would be a bit easier for you to figure out on your own....but as long as you do all the above tests, in the exact order I prescribe, and report back all of your findings....we should be able to get you back on-the-air...)


A few specifics, in red...

Originally Posted by mdsilvers

Hello everyone. I am having a challenge troubleshooting a power issue in transmit for 6,4,2 megs.
On a side note, you'd be the first cruiser I've known in over 30 years that has tried 2mhz!!! Too much noise, and too poor antennas, for most small boats to have much success past 50 miles!


I have the icom 802 with dynaplate and whip antenna on my catamaran. I am booming on 8megs. Today I moved to 4 megs to avoid a skip and realized I have virtually no power.
Although, fairly irrelevant to what might be wrong with your HF radio system....I'm curious as to what communications range (approx. how many miles), and at what time of day, you found 8mhz to be unusable, but were hoping that 4mhz would be better???
(typically I advise using the highest freq that will support comms for a specific distance and time of day...)



If I whistle in the MIKE on 2,4,6 I get 1-2 bars and am very faint 1/5 on signal compared to other boats. If I do the same whistle test on 8 megs I get full bars.
Switching to "FSK" mode (F1B), allows you to transmit a unmodulated carrier with just the press of the mic button...


So, not sure what I need to check. All connections are good and I consistently have one of the stronger signals on 8megs so not sure what I need to check.
See all the above notes, do all of those tests, in order, and report back....and we'll get you going....


Thx in advance.
You're welcome!

BTW, there are lots of troubleshooting advise here on Cruiser's forum....but thought it best to simply address your specific issues directly, rather than pointing you to other similar recent threads...

But, if you look here...you'll find a plethora of reference and resource material...
http://www.cruisersforum.com/forums/...tc-133496.html



And, Mark, AFTER we've got you all fixed up....and, if you have decent and cheap internet, then I suggest you watch some free YouTube videos!!

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




I hope this helps..

Fair winds..

John