Zero power on transmit

[PeterBld]

We bought "Wild Turkey". She was renamed "Marionette" and was moored in Panama in Gatung Lake for about 20years. Then bought by a Swiss couple who renamed her Toskuma sailed her to NZ where we bought her. We have almost completed a full refit. Not much left we have to replace. Resigned. Rewired. Replumbed. New electronics. Cabinetry. Gas fitting. Squabs. Sails. Running rigging. Whew!!!
I need some help. The SSB is a Icom 706 Mk11. Bench tested fine. Powered up well. But in the boat we get zero on transmit. The counter poise is copper sheet through most of the hull. But the bonding straps in the lazzarette have corroded so only have around 1.5sq metres (sorry we are Kiwis so cannot use imperial measurements) I am wondering if this is why we are not getting power on transmit??. Anyone have experience with this? We have a Dynaplate ready to fit on our next haul out. Checked all other connections for corrosion. They look good. Aerial is via a SGC Auto tuner then short 12g wire to an insulated back stay.
Appreciate any advice but please use simple layman terms as I am not experienced in this field. No jargon please. I struggle to follow some of the threads.

 

[Don S/V ILLusion]

The counterpoise has nothing to do with output power. It only affects the radiation pattern and efficiency of the antenna. And even a "bad" antenna will not prevent the radio from having a small amount of output power. So the problem causing no power is elsewhere.

Absent more info, this is a guessing game, I.e., low DC power?, short in tuner or coax connectors?, operator error?,

 

[PeterBld]

So the problem causing no power is elsewhere.

Absent more info, this is a guessing game, I.e., low DC power?, short in tuner or coax connectors?, operator error?,[/QUOTE]

Ok. That helps narrow the search. Thank you .

DC power. Off a 500ah battery bank. About 13.2v at the radio. About 12.5v at the tuner. (10 metres of wire to the lazzarette. ) coax aerial wire shows a good circuit when disconnected both ends. I have not checked the short wire from the tuner to the back stay. I will do this today but this is a new wire and just been installed and was firmly attached at the tuner and back stay.
Operator error. Aha!! I am way less than skilled at this. Tx has been set at Hi. Mic has been set at 6. Using USB. Tested on 2182 in daytime here to NZ Maritime and they say no signal received. They transmitted back and I had no receive at my end.
"Short in the tuner" ? Any suggestions as to how I may test this?

 

[Brian D]

The Icom IC-706MkII is an Amateur grade transceiver. Bear in mind that if you just key the mic while you are in USB you will have no perceived power output. You can change the operating mode of the radio to FM and try again. Pick a frequency in the 10 meter band between 28300 and 28600. When the radio is set to that band and the mode to FM, key the mic. You should see the meter move indicating power. Note, you need to be a licensed amateur radio operator to test on these frequencies. I specifically selected the higher frequencies because band conditions are very bad and you will not interfere with anyone. Your choice to try this test.

For a receive test, go to 2.5MHz, 5MHz, 10MHz, 15MHz, 20MHz, or 25MHz and listen for a time signal. Don't forget to tune the antenna tuner. Someone in the world is transmitting a time signal. In your area you should hear China and possibly Korea.

Also, make sure the RF cable is connected to the TOP most RF connector. The top is for HF and the bottom one is for VHF/UHF.

Finally, one must assume that your radio has been "opened" up to operate on ALL frequencies between 1.6MHz to 29.999MHz. If not, they you will be heard anywhere except the ham bands. Marine frequencies are not available on ham equipment.

Don is correct about the counterpoise. The antenna tuner will work with or without a counterpoise. To make you feel good, you may make your own. If you have access to wire (18 AWG) you can cut four lengths of 10.21m, 5.46m, 4.97m, and 4.27m. Electrically tie the four wire together and connect to the antenna tuner ground lug. At least you will have a working counterpoise.

 

[Don S/V ILLusion]

. They transmitted back and I had no receive at my end.

Assuming they have a generally strong signal and you hear nothing, we can rule out a 12v DC power problem, operator error and connector shorts as none of these would cause complete loss of receive signal. Given you stated the radio 'bench tested fine', I assume you did transmit and receive signals as normal and it's not a problem internal to the radio.

I can think of no issue which would cause the problem. Hope greater minds prevail.

 

[steve stark]

I'll throw in my 2 cents worth....
I find it curious that you are measuring 0.7 lower at the tuner than the radio. What was your reference for the voltage measurement (i.e. where was the negative lead of the meter for each measurement)?
If your black meter lead was on a ground near each positive voltage measurement point, then you may have a DC ground problem. Here are some possibilities:

1. Your negative lead from battery to radio may be fused. If so, the fuse might be open, and your voltage measurement is being referenced back through your coax/RF ground. This would result in 0 transmit power when keyed.
2. If not fused, integrity of the DC negative wire needs to be checked from battery to radio to tuner. I am assuming the tuner is getting power from a battery connection. If not, it may be getting power through a tuner port on the radio.
   
3. If power is OK, then what about the tuner? If the radio benched tested OK, was the tuner also in the bench test. You can disconnect the aerial coax from the tuner end, touch the center pin of the coax to the backstay lead, and you should get reception. Don't key the transmitter while doing this. If you get reception while the tuner is thus bypassed, then the tuner either has insufficient DC power, or is defective.

 

[PeterBld]

1. ng this. If you get reception while the tuner is thus bypassed, then the tuner either has insufficient DC power, or is defective.

[/QUOTE]

The voltage drop was between the dc at the radio buzz bar and the dc at the lazzarette just before the tuner. It was tested on the + and _.
The fuses at the radio are fine. I will check in the tuner to see if there is a fuse there.

The tuner was not part of the bench test so I will try the direct aerial to back stay for reception only.

 

[Don S/V ILLusion]

Not familiar with all the SGC tuners but if you have the ubiquitous 230 model, there are no internal fuses. Variants might...

 

[PeterBld]

The Icom IC-706MkII is an Amateur grade transceiver. Bear in mind that if you just key the mic while you are in USB you will have no perceived power output. You can change the operating mode of the radio to FM and try again. Pick a frequency in the 10 meter band between 28300 and 28600. When the radio is set to that band and the mode to FM, key the mic. You should see the meter move indicating power. Note, you need to be a licensed amateur radio operator to test on these frequencies. I specifically selected the higher frequencies because band conditions are very bad and you will not interfere with anyone. Your choice to try this test.

For a receive test, go to 2.5MHz, 5MHz, 10MHz, 15MHz, 20MHz, or 25MHz and listen for a time signal. Don't forget to tune the antenna tuner. Someone in the world is transmitting a time signal. In your area you should hear China and possibly Korea.

Also, make sure the RF cable is connected to the TOP most RF connector. The top is for HF and the bottom one is for VHF/UHF.

Finally, one must assume that your radio has been "opened" up to operate on ALL frequencies between 1.6MHz to 29.999MHz. If not, they you will be heard anywhere except the ham bands. Marine frequencies are not available on ham equipment.

Don is correct about the counterpoise. The antenna tuner will work with or without a counterpoise. To make you feel good, you may make your own. If you have access to wire (18 AWG) you can cut four lengths of 10.21m, 5.46m, 4.97m, and 4.27m. Electrically tie the four wire together and connect to the antenna tuner ground lug. At least you will have a working counterpoise.

 

[PeterBld]

Checked the RF cable, yes it is on the upper connector

 

[PeterBld]

Thank you for all your comments, really appreciate the help. I am well used to using SSB but only as a user, not as a trouble shooter, and your comments are all appreciated.
Please keep the tips coming.
Pete

 

[Brian D]

Time to hook up a dummy load to the back of the radio and key at 100 watts on CW. Then at the connector to the tuner. Same test, 100 watts on CW. I hope you have access to a dummy load.

One more thought. I accidentally put my Yaesu radio in split mode and could not figure out why it was not transmitting any carrier through my watt meter. Might want to check that.

Can you receive anything? As I mentioned before, the bands are not the greatest in the world right now.

 

[PeterBld]

Yikes - dummy load. ??? Can you enlarge on this please.

Split mode ?? Again, please excuse my ignorance. What is this?

 

[Don S/V ILLusion]

Yikes - dummy load. ??? Can you enlarge on this please.

Split mode ?? Again, please excuse my ignorance. What is this?

A dummy load is any 50ohm resistive load capable of tolerating the transmitter output power for test purposes. If you don't have one, you can improvise with a 100w lightbulb in its socket while connection the leads to the antenna coax connector center pin and ground.
Split refers to transmitting and receiving on different frequencies. If your radio is in split mode with the Vfo(frequency control) set out of band, it will not transmit. But as it doesn't receive either, that is likely not the problem.

 

[Brian D]

Sorry Peter, I should have explained. Yeah, a 100 watt light bulb will work just fine. Short piece of coax cable to the bulb and if your transmitting, the light will glow or flicker with your SSB signal.

 

[PeterBld]

Thanks again for your patience with a new boy in this field.

My partner and I are off for two months to Europe next week (glug - got my knife and bullet and bomb proof underwear packed already) (struth - Europe is getting as dangerous as USA) so I am unable to try out these suggestions till we get back in October.
Please let this thread remain open, and any further suggestions are welcome, I can keep on this forum whilst away.

Pete

 

[Brian D]

Peter, regardless, keep your system up and running. Stay on a cruising frequency and if you hear someone give them a call. It just might be something simple like you being in a location that is not favorable for HF comms.

Good luck and safe passage.