HF Radio Questions -- Atlantic Crossing

[Cadence]

Something as simple as a mike?

[Dockhead]

Originally Posted by Cadence

Something as simple as a mike?

First on my list.


It was from Zen and the Art of Motorcycle Maintenance (I think) that I learned to start with the simple stuff.

[jt11791]

How is the antenna tuner connected to the antenna? That's a common place for a bad connection as it is often out in the weather.

[donradcliffe]

Hot tip. Its single side band mate. It doesn't put any carrier power out. Whistle into the mike.

Also--don't trust digital power meters for radios.

[Wotname]

Originally Posted by Dockhead

Hot tip.


So on H3E at 2182, not even a flicker.


So besides a bad mike, could be blown out finals I think.

OK, if no power out with H3E (or A3E) modulation selected and mic keyed (i.e. Tx annunciator active), then you need not worry about the microphone being serviceable (unless you have two faults ).

So it's either the power supply or the transmitter circuit.

With A3E (and I believe H3E), you should get maximum current flow through the power supply circuit even when not modulating as you are transmitting full carrier wave at max TX power ( no need to whistle etc). Check the voltage at the back of the radio while keying the mic (Tx annunciator active), if OK then the problem lies within the transmitter. If voltage not OK, then problem lies with the power supply.

[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!

[Discovery 15797]

Originally Posted by Catboat Willy

Many of the Icom marine radios will not transmit until there is an identification number (similar to an MMSI number here in the states) programed into the transmitter. It will receive but not transmit.

This is incorrect.

A radio will not transmit a DSC call if there is not MMSI programmed into the transceiver.

However, it will still transmit on marine channels and ham frequencies.

[RaymondR]

The old ship station operators used to tape a small neon tube indicator to the antenna feed line to tell at a glance that the unit was transmitting.

[Siberian Sea]

This happened to my HF radio once and the issue was low voltage to radio. Perhaps you should put a multi meter and check both power supply and ground connections

[Brian.D]

Originally Posted by RaymondR

The old ship station operators used to tape a small neon tube indicator to the antenna feed line to tell at a glance that the unit was transmitting.

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.

[El Pinguino]

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.

That was back in the old fashioned 500 kcs days, was when no co-ax was involved - just hard copper maybe 1/4" diam straight out of the top of the transmitter to a big insulator on the radio room bulkhead.
Radios like this old BAS one on display in the Stanley museum, F.I.

[RaymondR]

A lot of them used copper tubing and the radios were big hefty beasts or 19" racks with separate units for battery chargers, antenna tuning, transmitters and receivers. They usually had two battery banks which they switched on alternate days. All this stuff was usually installed in a separate radio room.

[Wotname]

Come in Rangoon

Sparks

https://www.youtube.com/watch?v=sNmfmT_G9ec

[El Pinguino]

Somebody was multitasking here
https://www.radioofficers.com/galler..._022-modified/
Key down while taking a photo - complete with neon.

[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...


b) As I have been saying for a couple decades now (and is in the stickies above!), the Icom marine HF radios display "TUNE" if the tuner has supplied the radio with acceptable SWR (of ~ 1.7:1 or below)....and it flashes "SWR" if the SWR is ~ 1.7:1 to 2:1....and "SWR" is displayed continuously if SWR is > 2:1...."THRU" is displayed if the tuner is unable to find an acceptable SWR and tuner is then bypassed ("SWR" is displayed when attempting transmissions, when tuner is bypassed and display shows "THRU" in receive)....

Also, most Icom marine HF radios (such as the M-802, M-801e, M-710, etc.) indicate approx RF power output, at ~ 15 - 20 watts per segment of display illuminated....

So, without any external SWR / Power meter, you can use the front panel display, along with any DC power measurements to fairly easily troubleshoot transmit issues....you can see approx power output and approx SWR, without any external metering...

I have no clue how / why some of the myths continue, but here are the facts!


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).

--- If you do see full deflection / illumination on the antenna current / power output display, that means all is good! (but you'll now need to figure out why you have no or little output in SSB Mode)

--- If you see "TUNE" indicated, but have little power output deflection then you do have a problem (could be a DC power issue, could be a coaxial cable / connector issue, etc.)

--- If you don't see "TUNE" indicated on the display, chances are the tuner is not getting a "Start" signal, and therefore isn't tuning, and hence little output from M-801e. (there is an internal 5 amp fuse, inside the M-801e, that could be an issue....or could be control cable issues, or coaxial cable / connector issues)


---- Back to: if you do see full deflection / illumination on the antenna current / power output display (in FSK carrier), but still have little, to none, output in SSB Mode....it could be a microphone or handset issue (the M-801e comes with the telephone-style handset, not a microphone....and some have had issues trying a different mic, so look for an Icom HS-98 handset, or Icom HM-135 mic, to test this M-801e)

Also, be aware that I'm not certain if the M-801e has its internal DSP-based Speech Compressor turned on as standard (or, like modern M-802's, it needs to be turned on by dealer / installer, via software)....but, if you do see good power output in FSK/F1B mode, but NOT in SSB mode, and a new mic or handset doesn't correct the issue, this would be my first, best guess!!!

Fact is the standard M-802 SSB modulation levels were factory designed / set (not adjustable!) based on the DSP-based Speech Compressor is active (on), and when it is off the SSB power output is low (even loud voices / whistles, are usually only deflecting the output display 1/3 - 1/2 of the way)....technically the "peak" power is still the max (125 watts for the M-801e from 4mhz -26mhz, and 85 watts < 4mhz), but the average power is very low...
This is a known issue on some M-802's that never had their speech compression turned on, and if this M-801e was installed 10 years ago (and nobody has used it since?), all bets are off as to what might be the issue here, but these are my best guesses based on the info provided so far!

{btw, this speech compressor issue doesn't effect DSC or data comms, just as the old "clipping issue" and factory update/mod didn't effect DSC or data comms, only SSB Voice....so try some DSC Calls to coast stations, too}



Hope this helps.

John


P.S. My first marine SSB install (in 1973) we used a Bird 43 watt-meter AND fluorescent light tube taped to the backstay to make remote antenna tuner adjustments (this was BEFORE auto-tuners), had to set-screw/clamp TWELVES wires on a coil, then adjust TWENTY-FOUR variable caps....one coil tap and two capacitors for each of the 12 channels....
My point is: we did the coil tap positioning and coarse adjustments of the caps, with the watt-meter (swinging the slug around all-the-time), and the final, fine-adjustments looking at the fluorescent tube, verifying its maximum brightness (which corresponded to maximum antenna current, even if not exactly the lowest SWR)...
Ah, those were the days!