Icom AT-140 tuner with M802 HF radio (SSB) stopped tuning

[JohnT]

Get to South Africa with a "buddy boat" in VHF distance who can do weather or If you have an iridium phone, send your daily position to Sam, SAMMN, at zs1sammnet@worldonline.co.za and he will send your daily WX and warnings. Or send me a PM and I will route you via sat phone SMS. If you have no sat phone, a buddy boat is your option.

When you get to SA you can have your 802 repaired at Multisource in Johannesburg.

You need to soon make a move out of the region as cyclone season is soon to start.

John.

[JohnT]

Forgot to say: Start listening to Sam on 14.316 MHz @ 11:30 UTC and see if you can receive him - he tx's to the Indian Ocean first then swings his beam to the Atlantic.

John

[Jim Cate]

One solution not yet mentioned is to buy a manual tuner for the short term use of your radio. Not as convenient as the auto tuner, but pretty fool proof... and inexpensive, too!

FWIW, I've used a manual tuner (MFJ Versa tuner II) now for over thirty years of maritime mobile service. Cost something like 150 bucks when new, still going strong.

Jim

[SoonerSailor]

Originally Posted by Jim Cate

One solution not yet mentioned is to buy a manual tuner for the short term use of your radio. Not as convenient as the auto tuner, but pretty fool proof... and inexpensive, too!

FWIW, I've used a manual tuner (MFJ Versa tuner II) now for over thirty years of maritime mobile service. Cost something like 150 bucks when new, still going strong.

Jim

Turns out the M802 of the OP is simply not putting out RF.

But I too have used a manual tuner when I was having trouble with the AT-140. The SWR loss at typical HF frequencies associated with having the tuner at the radio end of the coax going to the backstay was not debilitating, and I was still able to make connections without undue trouble.

Chip

[Jim Cate]

Originally Posted by SoonerSailor

Turns out the M802 of the OP is simply not putting out RF.

But I too have used a manual tuner when I was having trouble with the AT-140. The SWR loss at typical HF frequencies associated with having the tuner at the radio end of the coax going to the backstay was not debilitating, and I was still able to make connections without undue trouble.

Chip

No need to run coax to the backstay. GTO15 works fine and has little effect upon the SWR. Becomes part of the antenna, of course, and may be awkward to route through the cabin.

As I have posted many times, I just run the whole rig as my antenna, no insulators other than the hull. In this case, the feed from the tuner to the chainplate is a mighty 18 inches long!

But this is a digression from the OP's dilemma, so I'll bow out.

73,

Jim

[SoonerSailor]

Oops. I meant coax to the non functioning AT-140.

[Daurin]

Bill,

Originally Posted by btrayfors

All this long-distance guessing is disturbing to me, in the extreme. For want of a good SWR/power meter and a dummy load....
...THEY ARE WIDELY AVAILABLE...
...but I'm really tired of this when the resolution is very simple and cheap.

I agree, and these should be aboard before leaving home, as they are NOT widely available. They would have expedited diagnosis in my case, but certainly not resolution.

Originally Posted by btrayfors

Don't ignore the tuning/control cable...
...Tuners do go bad, too.

As indicated above, the control cable was not the issue (though it did need overhaul), nor was the tuner itself. The problem was in the transceiver/transmitter, and yes, with an SWR/power meter, I would have known this much sooner than I did.

Dirk

[Auspicious]

Originally Posted by btrayfors

All this long-distance guessing is disturbing to me, in the extreme. For want of a good SWR/power meter and a dummy load.......

NO BOAT SHOULD LEAVE PORT WITHOUT THESE TWO VITAL PIECES OF GEAR. FOR A TOTAL INVESTMENT OF UNDER $100 THEY ARE WIDELY AVAILABLE AND WOULD IMMEDIATELY HELP TO DETERMINE THE PROXIMATE CAUSE.

You will spend a bit more than Bill proposes but I suggest this SWR/power meter: https://www.universal-radio.com/cata...ters/2140.html because it provides valid numbers at VHF as well as MF and HF.

I use this dummy load http://amzn.to/2zQm7jy . Power handling is limited but you can turn down the power from your HF/SSB and get quite good data. It's test equipment, not in use all the time. I have two.

Total cost around $200.

[Daurin]

Thanks for the great tips.

[Daurin]

Resolution: After nine weeks without comms, our new radio arrived here in Reunion this afternoon. It's installed and working fine. When we get back to the states, I'll probably send the old one back to Icom for a new transmitter board.

Thanks again to everyone who chimed in!

[Robert Tilbury]

Originally Posted by btrayfors

All this long-distance guessing is disturbing to me, in the extreme. For want of a good SWR/power meter and a dummy load.......

NO BOAT SHOULD LEAVE PORT WITHOUT THESE TWO VITAL PIECES OF GEAR. FOR A TOTAL INVESTMENT OF UNDER $100 THEY ARE WIDELY AVAILABLE AND WOULD IMMEDIATELY HELP TO DETERMINE THE PROXIMATE CAUSE.

Sorry for the rant, but I'm really tired of this when the resolution is very simple and cheap.

Don't ignore the tuning/control cable. The connectors at each end are a disaster....not waterproof and very prone to corrosion and breaking when you attempt to remove them. Also, I've seen a NEW control cable defective in a NEW 802 installation in Annapolis. Apparently it was stressed too hard during installation, and had broken conductors inside. Replaced the wire and bingo: everything now worked.

Tuners do go bad, too. However, the AT140 is an excellent piece of gear and it is very well waterproofed....unlikely to be compromised inside. EXCEPT, as mentioned, sometimes the mechanical connections inside are not tight, especially for the ground.

FWIW,

Bill
WA6CCA

Bill the rig has no TX ,,

[coconha]

Hi, I currently have very similar problem. I did some debugging and will describe it next. But first the symptoms:

- When I press Tune, I hear 1 click on both at140 and m802, but the outcome is Thru 99% of the time. It seems if I try long enough (for example, 20 times) the outcome is multiple clicks and a Tune outcome.

- People reported my transmission is very weak to the point they cannot understand me.

- 6 month ago, these problems did not exist.

The set up is as follows: The at140 is in the lazareth connected to an insulated backstay. The counterpoise is a copper tape connected to the at140, m802 and a keel bolt. There is a 1uF capacitor between at140 and the tape. (There is a history to that capacitor, described later)

Here is what I tried so far without sucess:

- The antenna deck insulator looked a bit cracked and I replaced with a new one

- Cut both ends and respliced the 14awg wire connected to the backstay.

Now for some things that puzzle me:

- I disconnected the copper tape from the keel bolt and also disconnected the mast lightning protection from the keel. Keel is no longer wired to anything. Using a multimeter I can verify that there is a unexplained connection between the keel and the battery negative. It gets weirder, when I place the black probe in a keel bolt and the red proble in the battery negative the multimeter beeps and reads 0.0 ohms, but if I swap the probes around, the multimeter reads open loop. It seems there is a "diode effect", but all keel bolts are free from any conhection. I am assuming this unexplained battery connection has a detrimental impact to the counterpoise performance

- I get a multimeter beep when I test for continuity between the at140 ground lug and the battery negative. Now that is not a new thing. The previous boat owner claimed this is an undocumented "feature" of the at140. He told me this connection was the reason he lost a saildrive to galvanic corrosion in a hot marina in the past. He added the capacitor and a new sail drive and claimed no problems ever since.

Anyone has any tips of advice on what could help? Thanks in advance.

[coconha]

The stainless washer of the deck insulator lug was posing a resistance of 40 ohms. A bit of sandpaper and now all is good.

I also found out why I was measuring this "diode effect". You cannot measure continuity with a multimeter on a live circuit. By "live" I mean battery is switched off but as it turn out, I measured 0.5V between the battery negative and the keel. I was a bit shocked with that voltage as I am assuming this is due to galvanic potentials between keel (lead with copper based antifoul) and saildrive (aluminium). The last anode on the saildrive lasted 3 years though.

[coconha]

Not all is good yet. I attempt to use the radio twice a day, but it seems sometimes it will not tune. I generally leave the radio powered off and power it on just before attempting to use it.

However, I observed and interesting thing. On 3 occasions after a failed tuning attempt, I left the radio on and after a while (several minutes), the radio would tune and transmit successfully..

Not 100% sure yet, but it seems the radio needs to "warm up" sometimes. Is that a thing?

[Brian.D]

Coconha, you are best served if you start a new thread instead of tagging along on an old thread. This way your info and findings will be at the top of the thread and not buried three pages down.