Single Sideband Question

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windjunkee

Member III
This is a very esoteric question, but here goes: I purchased a used Kenwood TKM-707 SSB radio for the boat. For hooking it up, I bought a Shakespeare 23 foot antenna and an ICOM AT-130 Antenna Tuner/Coupler. I believe the grounding is good and the installation/wiring looks to be in order. I had the Kenwood bench-tested and it was fine.
However, when it is hooked to the tuner, I cannot get the tuner to work. It powers up, but it does not tune, thus, I cannot transmit. We have traced it to the transceiver-tuner connection, but the wires are new and we followed the manual to the letter for connecting one to the other.
My understanding is that when one dials to a desired frequency, the antenna tuner is supposed to go through a series of switches to match the antenna to the frequency. The process is supposed to take somewhere in the range of 15 seconds to tune the antenna but we get nothing. The transceiver theoretically, sends a low voltage signal or pulse to the tuner which tells it to start tuning. However, our set up seems not to be doing that. We tried to jury rig a bypass with a schematic we obtained through ICOM with similar unsuccessful result.
I have been told both that the ICOM AT-130 is a universal coupler designed to work with any SSB transceiver, and that the ICOM AT-130 only works with ICOM radios. Before I go out and buy a new ICOM, I want to exhaust every avenue to make the system I have work. Anyone have any ideas?

Jim McCone
Voice of Reason E32-2 Hull #134
Redondo Beach, CA
 
bnye

bnye

Junior Member
TUNE Indicator

Jim,

Here is a link that might give you a clue.

http://www.eham.net/reviews/detail/3091

When you do a manual TUNE Operation, does the TUNE indicator flash?

Based on my limited Kenwood experience, If the TUNE indicator does not flash, it means that the control signal leads on the antenna coupler connector is not wired correctly and the radio does not believe that an antenna tuner is connected and will not output the carrier signal necessary for tuning.

Warning, I don't have direct experience with the 707 so take this as a semi-educated guess only. :0305_alar YMMV

Bill
 
H

Howard Keiper

Moderator
When you say the grounding looks good, just how good is that? Please describe that in detail. A reasonably modern tuner can tune a wet string. Have you had the tuner looked at when you had the radio checked out. the tuner must be in close proximity to both the radio (and it's ground), and the antenna.
My bet is the ground or a faulty tuner.
Howard Keiper
Sea Quest
Berkeley

P.S. A SSB transmitter does not output energy until you modulate it. Clicking the mike key produces nothing...to properly modulate, whistle with as clean a tone as you can muster.
 
W

windjunkee

Member III
Bill, Thanks for the link. I read both posts and they seem to describe the problem to a "T". Now, we did email a guy at ICOM, who sent us the schematics for the "Black Box" which is referred to in the second post. However, we're not getting any different result from using the black box (we have it rigged up as a button and an LCD light -- press the button and the start voltage gets sent to the tuner and the LCD supposedly stays on until it is tuned) I'm going to check into the grounding of this jury rig when I get the chance.

Howard, we had the grounding done by a professional. He did several things: He bonded 4-inch wide copper to the hull along the underside of the deck to shield the wires between the antenna and the radio, then ran a strip down the hull into the bilge under the engine where he criss-crossed it a few times and then tied it into one of our thru-hulls using stainless hose clamps. The ground is attached to the tuner and to the radio. The tuner and the radio are about 5 feet apart. The tuner is about 3 feet from the antenna

Jim McCone
Voice of Reason E-32-2 Hull #134
Redondo Beach, CA
 
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