HF Radio Questions -- Atlantic Crossing

[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.

[Brian.D]

Not to seem like being a jerk, but have to ask what mode are you working in? Could you possibly be stuck in digital mode and not SSB? Just asking.

[S/V Illusion]

Assuming you are on SSB, the “flicker”is a sign of low voltage. Not apparent in receive mode as the transient voltage draw going into transmit will exacerbate any loss due to poor connection in the power supply chain. Don’t just look at connections; remove and clean each.

[Dockhead]

Originally Posted by Brian.D

Not to seem like being a jerk, but have to ask what mode are you working in? Could you possibly be stuck in digital mode and not SSB? Just asking.

Not a jerk at all. I've selected J3E (USB) above 10mhz; LSB below. But I'll check again if one of the canned "email" modes isn't selected -- thanks!

[Dockhead]

Originally Posted by S/V Illusion

Assuming you are on SSB, the “flicker”is a sign of low voltage. Not apparent in receive mode as the transient voltage draw going into transmit will exacerbate any loss due to poor connection in the power supply chain. Don’t just look at connections; remove and clean each.

THanks; hot tip!

[Brian.D]

OK... good luck. I wonder... does Marine SSB use LSB? I am not sure. I know that HFFAX transmissions are all USB. Hmmm... curious.

Also, wouldn't there be an indication of lower DC voltage when keying the radio, meaning, the radio's lights would dim, or the relays would chatter. Something.

[Jammer]

Originally Posted by Dockhead

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

It really helps to have a SWR/power meter and a dummy load to troubleshoot stuff like this. Otherwise it's just guesswork. You can get a usable SWR meter, dummy load, and connectors for under $300.


In essence you connect the SWR meter between the transceiver and the antenna, observe readings, and then you know whether the problem is with the transceiver or the antenna system (including tuner).

[S/V Illusion]

Originally Posted by Jammer

It really helps to have a SWR/power meter and a dummy load to troubleshoot stuff like this. Otherwise it's just guesswork. You can get a usable SWR meter, dummy load, and connectors for under $300.


In essence you connect the SWR meter between the transceiver and the antenna, observe readings, and then you know whether the problem is with the transceiver or the antenna system (including tuner).

Good to have generally but in this case with no output, they are of no help.

[Brian.D]

Going off track here, but if one puts an SWR between the radio and the antenna, in this case a single wire antenna, one may not get much of a reading. The SWR should be between the radio and the tuner. If the tuner is tuned correctly, then the reading should be 1:1 or there about. If the tuner is NOT tuning correctly, then the reading will be way off, possibly 25:1 or higher.

One must remember that a tuner not only matches the antenna, is must also match the radio. There are two sides to a tuned circuit; source side and load side. Both sides mush be correct in order for the RF to be transmitted. But, caveat here, the antenna is never really "tuned", only the circuit connected to the antenna is matched impedance wise. So much going on.

Let's find out why you are not getting any RF out. Could be the DC power as mentioned before, but it also could be the tuner is NOT matching to the radio. This will present an impedance mismatch and the radio may see it and say "no fricking way am I going to send energy just to have it sent right back to me" kind of thing.

Again, sorry for going off topic.

[Stewie12]

Without an SWR meter you will not know your output.

[Wotname]

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

[Wotname]

Originally Posted by Brian.D

OK... good luck. I wonder... does Marine SSB use LSB? I am not sure. I know that HFFAX transmissions are all USB. Hmmm... curious.
.........

AFAIK, marine HF bands are all USB.

[wayne.b]

Originally Posted by Wotname

AFAIK, marine HF bands are all USB.

===


That is correct, all marine frequencies are USB. On the ham (amateur radio) bands it's LSB on 160, 75, and 40 meters. USB on all higher frequency bands.

[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.

[Pizzazz]

Really good suggestions. The first step should be to confirm power draw on transmit. Make sure the radio is in High power, your mic is not dead and radio is configured. Try transmitting a DSC message or just tuning the radio. If you can't get past this most likely you have a hardware or configuration issue.

If you can draw decent power (you will notice as everything will start flashing on the boat), then you need to test the quality of the transmission. This is uiky to be a problem in your installation. Send a test DSC to confirm.