Icom 802 transmit troubleshooting help

[discovery]

Just headed out after 6 months in marina for hurricane season my 802 has worked well these past 12 years in bahamas/ Caribbean. This summer I sent mic in to be replaced due to crumbling cord. Tried to use for first time now that we are down in Fla keys. Problem is I can receive but when I key mic to transmit I get nothing. No bars no fkicering lights nada. Confirmed im not transmitting by fellow boater calling me and heard no reply. I took my Mic to another boat and when plugged in it responded normally. Bars appear and lights flicker when it's attached on my unit there are no bars no flicker . when I do the fsk test I get 8 bars when I depress key on my like. Also see a surge in amps when I go to transmit by keying Mic.
I think I have eliminated the Mic as the issue since it seems to work fine on other units. Apparently the power circuits on subunit are good.. I receive ok. Can you help me determine what's the issue. As a side note the external speaker is working fine but the headphone jack seems to be faulty ,my headphones dont work now and I have tried ear buds also and get no sounds As I said this unit worked fine as recently as June.. Nothing has changed other than the new Mic.

[Brian.D]

Was the other radio you tested the mic on also an 802? And... did you test your radio with the other radio's mic? And... does your radio have a mic gain which might be turned down or turned off? And... does your radio have a mode that is not SSB that possibly got turn on?

[nhschneider]

I presume you’ve checked all your connections - the obvious one that can be problematic is where the GTO wire attaches to the backstay. However, if you’re receiving okay, then it’s unlikely to be the problem. Worth checking out, just the same.

I’m also assuming that you’ve looked at your tuner but they rarely give problems. Still, it might be worth having someone listen to the tuner as you key the mic to make certain that it’s doing its thing.

Sorry I couldn’t be more help.

Good luck, fair winds and calm seas.

[S/V Illusion]

Sounds like the PTT relay on your 802 isn’t working. In FSK mode, the relay is not needed to transmit which explains why it works in that mode and also eliminates any concern with the feedline, antenna and tuner.

It’s not a tricky repair if you can solder SMDs or know someone who can and the part can be bought direct from Icom.

[discovery]

Originally Posted by S/V Illusion

Sounds like the PTT relay on your 802 isn’t working. In FSK mode, the relay is not needed to transmit which explains why it works in that mode and also eliminates any concern with the feedline, antenna and tuner.

It’s not a tricky repair if you can solder SMDs or know someone who can and the part can be bought direct from Icom.

Thanks I'm in marathon florida waiting to jump to bahamas, I wouldn't feel capable of that repair will be up in Miami area for a bit while waiting for a weather window maybe I could get it done there. Frustrating that it developed this issue over the 6 months it wasn't even turned on. It was working on return in June .

[discovery]

Originally Posted by Brian.D

Was the other radio you tested the mic on also an 802? And... did you test your radio with the other radio's mic? And... does your radio have a mic gain which might be turned down or turned off? And... does your radio have a mode that is not SSB that possibly got turn on?

Yes it was a 802. Actually have 2 boats in anchorage that have 802s tried my Mic on their units and response was save as theirs. So I assume the mic( new from icom) is working . as far as those other modes etc I will check but I can't imagine any issues there

[S/V Illusion]

Originally Posted by discovery

Thanks I'm in marathon florida waiting to jump to bahamas, I wouldn't feel capable of that repair will be up in Miami area for a bit while waiting for a weather window maybe I could get it done there. Frustrating that it developed this issue over the 6 months it wasn't even turned on. It was working on return in June .

That’s when relays go bad - non-use is a bad thing for mechanical components. I’m just guessing that’s your problem from what you describe but a service tech can confirm that in 5 minutes. Replacing the relay might take 15 minutes.

[ka4wja]

discovery,
While I'm concerned about your mentioning of "lights flickering", as there should be no lights flickering on transmit....but thinking you may have some transmit RFI on-board that you have just decided to live with? So, I will ignore my concern for now, and just answer your questions...

Originally Posted by discovery

Just headed out after 6 months in marina for hurricane season my 802 has worked well these past 12 years in bahamas/ Caribbean. This summer I sent mic in to be replaced due to crumbling cord. Tried to use for first time now that we are down in Fla keys. Problem is I can receive but when I key mic to transmit I get nothing. No bars no fkicering lights nada. Confirmed im not transmitting by fellow boater calling me and heard no reply. I took my Mic to another boat and when plugged in it responded normally. Bars appear and lights flicker when it's attached on my unit there are no bars no flicker . when I do the fsk test I get 8 bars when I depress key on my like. Also see a surge in amps when I go to transmit by keying Mic.
I think I have eliminated the Mic as the issue since it seems to work fine on other units. Apparently the power circuits on subunit are good.. I receive ok. Can you help me determine what's the issue. As a side note the external speaker is working fine but the headphone jack seems to be faulty ,my headphones dont work now and I have tried ear buds also and get no sounds As I said this unit worked fine as recently as June.. Nothing has changed other than the new Mic.

Actually I disagree with s/v Illusion here....

Discovery, assuming I'm understanding you correctly.....you mention that your M-802 actually does go into transmit in SSB mode, but you have no output when speaking? And, you mention that you can receive well, and can transmit at full power (all 8 bars illuminated upon transmit) in FSK mode, so in my opinion it looks like the T/R relay is working fine, and I'm assuming you switched to FSK mode and simply pressed the microphone's Push-To-Talk (PTT) button (?), in order to output a full-power carrier in FSK mode, so it seems that the mic's PTT button is working okay...


BTW, I wished you had borrowed another boat's M-802 mic and tried it on your radio....that would have told us a lot...actually more than trying your new mic on their radio.....but, using what info we have here, have a look at these thoughts.

Also wish you'd made a couple DSC calls to verify both power output / transmit-receive, AND the DSP modulator....but, you can do those in a couple minutes, easy-peasy...so after you look at a few possible solutions, please do a couple DSC calls...


Okay here we go...a few quick things come to mind....(of course my first thought was "bad mic" and/or "bad mic cord", but you already verified those are good)

[BTW, except for making DSC calls (of course), please do all of these tests / checks with the M-802's power disconnected / unplugged!]

Of course the first step is to disconnect everything from the M-802, except the Icom stuff (RC-25, Mic, speaker, and tuner) and the two antennas, of course....then connect your GPS data and make a DSC call or two....and if that works, then try a SSB Voice call / contact...




a) Please have a careful look at your M-802's control head (RC-25), especially the mic connector and headphone jack??
'Cuz it's possible that your two issues (no transmit audio and no headphone output) are related. Did something get spilled/splashed onto them? Or corrosion? Or, did a pin break off?
(remember that the headphone jack is also the "clone" jack, where you plug-in the programming cable to upload/program the radio....so, perhaps someone did this 6 months ago? or perhaps earlier and something has gotten dislodged / broken and just now has moved around and shorted something out?)
After the obvious answer of "bad mic" / "bad mic cord", this was my very first thought, as I've seen some of my fellow hams short-out brand new radios by plugging in the wrong cable, etc....and since these two issues your having are physically next to each other, please have a very close look (after you do the easy-easy things below, if you still have no luck, come back to this, and open up the RC-25 and see what you can see)



b) A close second though is the RC-25 (M-802's Control Head) connection cable and its connections, to/from the Main Unit...this is the black cable and round mini-DIN connections....it's possible that they've come partially dislodged, and/or corroded, making a bad connection....

Sometimes just unplugging and plugging them in, 3 - 4 times, is enough to clean 'em and regain connection....but if you have some "de-oxit" contact cleaner, a quick squirt and then 3 - 4 plug/unplug sequences should clear them up....
Of course it's also possible that there is a kink/short/intermittent in this cable itself, so inspect closely...




c) A close third place idea is something external has shorted-out....
Do you have any other equipment connected to the M-802, such as a PACTOR modem, plugged-into the AF/MOD jack, and/or the ACC jack, and/or REMOTE jack? If these cables are shorted and/or the PACTOR modem is defective in some way, these could disturb / interrupt your transmit audio...

Of course the first step is to disconnect everything from the M-802, except the Icom stuff (RC-25, Mic, speaker, and tuner) and the two antennas, of course....then connect your GPS data and make a DSC call or two....and if that works, then try a SSB Voice call / contact...


~~~~~~~~~~~~~~
d) Of course it is also possible you have some configuration of your M-802 wrong/changed such as the modulation in/out selection, but I've not seen that effect the radio this way, but it is possible??
If none of the above have shown a solution, please have a look at the M-802's manual and check every menu configuration of YOUR radio, to be sure all is good....then proceed with the below...





If the above three (a, b, and c) ideas and tests do not point to a problem, and a solution, it's likely a problem inside the RC-25 and/or the M-802 Main Unit...if you can borrow another boat's RC-25 (and perhaps their RC-25 connection cable, too), connect to your M-802 using your new mic....if it works, you know the problem is in your RC-25 (which should be an easy / cheap repair), if it doesn't work, then you know the problem is in the Main Unit (and that will need to go to Icom or an Icom Service Center)...below are some additional details...




e) This item I'm not 100% sure about....hey, it's Sunday morning and I've got a lot gooing on here and don't have the time to look at the Serv manual....but, I think the M-802 (like most Icom radios made in >25 years) uses a electret/condensor mic, and as such requires DC power (from the radio, thru the mic cord) to function....if this connection is bad (inside your RC-25, or in the RC-25's microphone jack) you will not get any audio out of the mic, but your mic will work on another M-802...
And, another M-802's mic will do the same as yours, it will not work on your M-802...




f) The microphone amplifier IC (in the RC-25, I think) or the gate amplifier IC (in the Main Unit), could be bad....and those would require a trained tech to examine and repair....



g) Of course the DSP Modulator circuit could be bad....but that can be check fairly easily by making a few DSC calls.....since you have other boats nearby that have M-802's (where you tried your new mic), this should be an easy-peasy test....if the DSC calls go thru fine, we can assume the DSP Modulator circuit is good.....although there is a teeny-tiny chance that it could transmit/receive the DSC tones (which are FSK) but its firmware could be corrupted in order to not produce SSB audio modulation, but that is VERY unlikely!




{fyi, there are good Icom service centers that you can get your M-802 quickly....Williams Communications in Tallahassee, comes to mind, but have a look at Icom's website to see if he still services Icom marine radios...

Also be aware that a close lightning strike can do some damage to electronics that do not show up immediately, and if your RC-25's LCD display looks weird, or darker, etc., this can be an indication of a close strike, or perhaps other electronics on-board are flakey?

And BTW, you can buy/replace the RC-25 easy-peasy, if you don't have the time to ship it out for repair...}



I do hope this helps?

Fair winds.

John

P.S. If I was closer (I'm 200 miles away), I'd offer to come by with a whole 'nother M-802/RC-25 and cables, etc....and I'm leaving today, heading the other direction....


But, please do the tests above, and if you find you need a RC-25 quickly (and can't find one quickly), please let me know as I have spares! (I own THREE M-802's...)

[ka4wja]

Has anyone heard from "discovery"?

It's been 6 days....and I'm leaving in a few days, and was hoping to find a resolution to his/her troubles.

Btw, I sent a PM as well.

Fair winds.

John

[ka4wja]

Not sure why he didn't return here, but I did hear from "discovery"....his problem was just a loose connection between the M-802 Main Unit and the RC-25 Control Head....(apparently he didn't have it plugged-in all the way).

Here is the message I received from him:
"For other reasons I had to look behind my instrument panel for a serial number on my big and while there I checked the connection behind the 802 and wiggled it and reset it then replaced the panel and I turned the 802 on and presto .... I had transmission so it was a case of a loose connection."

So, I thought it would be good to post this here....for everyone here to learn from.

Fair winds to all.

John