HF Radio Questions -- Atlantic Crossing

[Wotname]

Originally Posted by ka4wja

Dockhead,
I'm quite tied up, so need to be brief.

a) I know the M-802 does not transmit AM....not even on 2182....AM went away a LONG time ago, and A3H ("AME" / "AM Equivalent" / A3E) also went away quite a while ago and is not a transmit mode designed in the M-802....therefore you will not get any output at all from a M-802 in AM Mode, and, I believe the M-801e is the same (the M-801e manual confirms this, but I don't have a M-801e here to personally confirm this) ....so, you can leave this red herring suggestion behind and proceed...

..............................
c) Turn on 801e, then select a maritime HF simplex channel (not a MF channel, as the M-801e is designed to reduce power below 4mhz), such as 8A (8294.0khz), press the Tune button to initiate the AT-141 into a tune cycle....confirm the upper line of the display (near the left side, on the upper line) shows "TUNE", then press Mode button to select FSK / F1B (not A3J / USB), then press the PTT button on handset or microphone....this will trigger the M-802 (and M-801e ??) to transmit a solid carrier....you should see full deflection on the M-801e's "antenna current" / power output display (bottom-left-side of display in "channel name" display mode....bottom-right-side of display in "frequency" display mode).
................
John

John, I would have sworn on a stack of bibles my early serial number 802 could transmit CW on a AM mode but as it has been about decade or more since I last owned it, I bow to your far more extensive knowledge of the unit. Perhaps I was confused with FSK however I am sure I could get the unit to transmit solid carrier somehow without any modulating input. Always handy when trouble shooting a variety of possible defects.

Also, please remind me how much (low) power is generated and presented to the tuner during the tune cycle.

[El Pinguino]

Originally Posted by Wotname

John, I would have sworn on a stack of bibles my early serial number 802 could transmit CW on a AM mode but as it has been about decade or more since I last owned it, I bow to your far more extensive knowledge of the unit. Perhaps I was confused with FSK however I am sure I could get the unit to transmit solid carrier somehow without any modulating input. Always handy when trouble shooting a variety of possible defects.

Also, please remind me how much (low) power is generated and presented to the tuner during the tune cycle.

Manual here for 802http://www.icomcanada.com/products/m...n%20Manual.pdf
Page 12 refers.

801E manual here
https://icomuk.co.uk/files/icom/PDF/...ion_manual.pdf
It only has A1A(CW) in receive. See the specs page 65.

[Wotname]

Originally Posted by El Pinguino

Manual here http://www.icomcanada.com/products/m...n%20Manual.pdf
Page 12 refers.

Thanks 'Ping, very helpful. Maybe I was using A1A to get CW - my memory needs a re-boot it seems

[Celestialsailor]

Originally Posted by Dockhead

That really could be it. I think I'll order a new one just in case.

If you have a "Key jack" you can just key(or cross the wires and see if there is any audible tone out. The other problem could be blown finals...I hope not though.I like the Mic suggestion too. Bought a Yaesu FT-950 used. It had this problem...jiggle the mic cable and it would randomly transmit. Bought a desktop mike and voi la! N6FAI

[Brian.D]

Nominal output power for tuning is usually 10 watts. Some tuners like <10 watts and some will tune with about 25 watts. But 10 watts should probably be the nominal output.

[waterman46]

Originally Posted by Wotname

No modulation i.e. dead microphone??
Is there power in AM mode when mic is keyed?

That's good question. Remember that SSB modes do not have high average output power and normal SWR and power meters do not respond quickly to the very short high peak powers of SSB. Use AM for power tests - as mentioned all you need to do is key the mic for full power output.



Also if you have nothing else, connect a 60Watt incandescent light bulb (do they still sell them?) directly to the output of the transmitter. In AM transmit, it should glow fairly bright. In SSB modes, it will just flicker when you speak loudly. This will test the transmitter separately from the tuner+antenna even without the SWR meter.



But do yourself a favor and get the SWR meter.

[Brian.D]

One more thought here if you do not have AM or CW modes, you do have tune mode. That will produce a CW carrier that is needed to initiate the Antenna Tuner. So if you hear the tuner tuning then you know that at least you are putting out RF of some type.

If you have a power meter (RF, not DC) connected between the radio and the tuner (an SWR meter will also work since it shows both forward and reflected power) you should see an output of approx 10 watts. Then at least you know something is working RF wise.

[BocaIII]

most likely voltage/power issue
Jack
W4GRJ

[n5ama]

If you suspect a voltage supply issue and there are multiple components involved, it may be helpful to start at the battery and work to the radio. Check each element/connector or whatever for voltage with the AM position of the transmitter keyed. If voltage is good at that point, move on down the line to the next element. If you experience some voltage drop, correct the problem, (but don’t stop until you get to the radio).

In a corrosive environment, you may have several things in the supply line reducing your supply voltage. It’s helpful to know which element/elements are causing you grief.

Good luck finding your problem. You can take some comfort that your problem isn’t intermittent. Trouble shooting a intermittent problem can make you crazy.

My guess would be mic or finals or driver???

Happy new year to all.

Originally Posted by carstenb

Dockhead I had a similar problem. Nothing I could do would let me transmit. A ham operator on Hawaii suggested taking every single connection apart, cleaning them and reassembling. After I did that, the system worked perfectly. I never did find out which connection was bad - they all looked fine when inspected visually

[Dieseldude]

Originally Posted by Dockhead

I'm getting ready for an Atlantic crossing on my friend's boat, and I'm trying to get the HF radio working.


It's a professionally installed Icom M801E, so quite similar to my own M802.


It receives fine and the tuner apparently works. The antenna is an insulated backstay, and the ground plane is two dynaplates. No corners were cut in the installation, which I guess was done as part of the original build in 2010.


But I can't seem to transmit. I get a slight flicker only on the power meter when transmitting, and I have not been able to make any contacts.


What could the problem be? Power is set to high; and I've tried other power settings as well.


Grateful for any tips.

To begin with, just the usual cabling termination checks. Do you have an amp meter to check current draw while transmitting? The manual should have the spec. If unsure, it will be roughly a bit more then the transmit power in watts divided by the supply voltage at full modulation. But typically voice into the mic provides less then this. This is single side band, so there has to be voice signal going into the mic to develop anything close to full transmit power. A steady whistling into the mic should provide steady modulation for steady current draw. Use proper procedure and ask any station for a radio check. Voice could cause jumpy current draw. Or if you have selective calling, the tone will give some steady modulation. Low current draw may mean just a bad power supply connection or ground. But it could also indicate an internal fault. Check over all the terminations. Also check antenna and antenna cabling and terminations. I'm assuming that the system has an antenna tuner somewhere near the antenna base, so don't forget to check cabling to that. Once you exhaust all the basic checks and if not solved, of course the technical troubleshooting begins. Don't forget your microphone. A bad microphone or mic cable can cause low transmit signal.

[Auspicious]

John got the good stuff so I'll just clean up around the edges.

There is circuitry in the output of the radio that rolls power back if the SWR is high. In my experience the most common cause of high SWR comes from the GTO-15 breaking at the commonly and poorly used hose clamp between GTO-15 and backstay which causes the tuner to give up. Hose clamps are really bad electrical connectors.

Like John I use FSK for testing. A screw-on dummy load is cheap. Check with RSGB and find a local ham with a power/SWR meter and a dummy load.

[StoneCrab]

Originally Posted by Wotname

If you don't have a discrete RF power / VSWR meter, connect a 100+W 120V incandescent light bulb directly to the RF output of the radio (i.e. before the tuner). This provides both a suitable RF load and RF power indicator for field testing purposes. The lamp will glow if you are transmitting.

Of course a power / VSWR meter and a dummy load is better - unless you don't have one to hand!

If that works, it is genius for those McGiver moments.

Does that actually work?

[Bill Balme]

Hi - I recently had the same problem on my 802 which had previously worked fine. I established that I had digital output - as I was able to use the Pactor modem, but no voice. I tried a new microphone - no good. I ended up returning to Icom who quickly found out that the cable between the main box and the control pad was not good. (a simple fix, but unfortunately the radio got damage in shipping back to Icom - so a $90 fix turned into a $500 fix!!!
So... check that cable specifically.
Good luck!

[paula_k]

I have to disagree. If the antenna or tuner swr is very high then the transceiver will cut output to protect the final amp transistors. Connecting a dummy load will provide a perfect 50 ohms and will isolate the problem to either the transceiver or antenna/tuner. An swr/power meter gives you better data on the transceiver output to the dummy load.
Btw, dynaplates are great for lightning protection but are a terrible rf ground. Even when you get things working don't expect a great transmit signal. A real professional installation would have included 100 sqft of copper in the sole or lining the bilge.
Paula NX1P

[Dieseldude]

Originally Posted by Brian.D

I believe that was when feed lines were balanced, like 300Ω or 450Ω ladder line. I do not believe that will work with coax. However, taping a fluorescence tube to the antenna wire will work. Maybe below decks at the tuner.

The florescent tube will not illuminate next to a coax antenna cable. The shield keeps energy from leaking out. It should illuminate next to the output wire of the tuner or the antenna itself if transmitter is putting put a good level of power.