Icom IC-7000 VHF/UHF Transceiver "Adjustment Mode"

Do a web search for iCom. They will answer your questions...

I would suspect a problem in the final output, or in the drivers. If you have the service manual, follow through by verifying the supply voltages to the final and modulator sections. Also, verify the carrier amplitude.

I don't know the unit, but also check in the user book to see if there are any settings for reduced power output.

I am assuming that all the standard procedures of antenna match and etc has been done...

Jerry G.

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1. Make sure the SWR on the UHF antenna is 1.5:1 or below. If ok it could be the hybrid output device. Not knowing the 7000 I would assume that it would have a separate output device for UHF. However I would verify the power input to the device and its voltage and AGC circuits before deeming it bad.

John-

If I understand, you are trying to increase power beyond 100%. My thought is that you are getting all you can with the hardware you have. The hardware may be defective and the computer can't compensate for that.

My problem is with frequency adjustment. When I enter the Adjustment mode, I can set the oscillator frequency to exactly what it should be. However, frequency returns to the previous value when I leave the Adjustment mode. If I re-enter Adjustment mode, the oscillator frequency goes back to the correct value, and again reverts when exiting Adjustment mode.

Do you or anyone else know what I might be doing wrong? Is there a step I'm missing that makes changes "take"?

Fred K4DII

Hi Fred,

I should have said the UHF is set to "100%", but it is putting out around 50 percent.

I am sorry Fred, I have no idea why you are having that issue with the frequency adjustment. I am assuming, after you adjusted, you pressed "F-4 (SET).

Would you please tell me if you can change the value on the display beyond the "Total Gain"? Simply rotate the main Dial and see if the number changes. On my IC-7000, no change occurs.

Thank You in advance, John N3AOF

John-

I don't have the ability to inject 3mV @ 1.5KHz into the microphone connector. Therefore I get zero output unless I speak or whistle into the microphone. Just rotating the main dial makes no difference. I don't see a number, just the output scale that reads up to 100.

I see that for "TX Total Gain(430M)", the correct output setting is 17.5 Watts. It isn't until a later step that you set (Po Max(430M) for 35 Watts.

If you can't get the power up to either value, the UHF amplifier module may have a problem. Since it isn't completely dead, you may decide to keep it that way rather than pay the price for a replacement. I wouldn't be surprised if you can buy a used IC-7000 for little more than the price of the module!

I'm sure I pressed the "F-4 (SET)" button. I suppose there could be a firmware upgrade needed.

Fred K4DII

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Hi Fred,

Just to see if the number, which is hexadecimal (digits from 0 - 9 plus A - F) changes located above the F1, F2 buttons, by turning the Dial, you don't need to input an audio tone. You need the tone to check the new setting afterwards on a watt meter.

FYI:

On my display are the following (via TX adjustments) for "PO" on 430M:

What are your numbers? I just want to see if they are far off from mine.

Thank You Again, John N3AOF

John-

Now I see what you are getting at. The Hex digits did not change when I turned the dial.

My numbers for 430M:

MIN 08

I checked power output on 430 (23 Watts) and 146 MHz (35 Watts) in FM mode. I did not check voltage under load. I'm using a little MFJ-4125P

Do you know if there has been a firmware upgrade for this radio?

Fred K4DII

Hi Fred,

Thanks for the Watt report on your radio. I assume you used a low SWR antenna or a wide frequency range quality dummy load.

Since I recently purchased this IC-7000 from the estate of a SK, I am unaware of a firmware upgrade, but it might be a good idea to check the Icom forum, if there is one at Icom's web site?

I will be checking for one in the next day or so.

Again Thank You, John N3AOF

Easy. Q401 or something around it.

See block diagram on Page 3-5 of the service manual. The driver blob, IC504, drives all the bands. There are 3 separate power amps. Q301/Q302 for HF, Q501 for VHF, and Q401 for UHF. Since everything except UHF is working, methinks everything up to and including the driver blob is also working.

I have no idea what's wrong, but I have a guess based on experience fixing one of these abomination. The solder connection between the rear panel UHF connector and the PA PCB is possible broken. Anything else would case zero power output. The fact that you have some power output means that the output stage is probably working, but little of the produced RF is making it to the watts guesser.

Ummm... that brings up an other problem. Make sure your wattmeter is working, accurate, and that you do your testing into a dummy load, not an antenna. There's nothing more frustrating that troubleshooting a working radio only to find your test equipment at fault.

Some free advice on working on the IC-7000. It's one of the worst mechanical radio nightmares I've ever had to deal with. Some hints and warnings:

Pulling the boards are hell because the self stripping screws are only good for perhaps a few insertions and removals before the threads are stripped in the aluminum casting. Be VERY careful when removing and inserting screws.

The plastic front panel on the radio section has a connector eventually going to the control head. Good luck getting it out and back in. Take photos of how the cable it tangled behind the panel or you'll never get it back together. Also, take photos of how the wires and cables are routed, as they're not obvious or easy to guess.

Removing the PA board is a mess. The driver blob, IC504 is attached to the casting by two inaccessible screws (someone forgot to drill clearance holes in the PA PCB). Therefore, you have to unsolder the leads to IC504 in 5 places in order to remove the board. Lots of other unsoldering to be done. See:

The circles and ovals are what needs to be removed before the PA board can be removed. IC504 are the 5 purple circles near the top.

Notice that the driver blob is still attached to the casting after removing the PA board:

Note the two (purple circle) solder points per UHF connector on the right. That's where I guess(tm) your problem is hiding.

Also, don't get any water into the radio. The multitude of flex PCB ribbon connectors on all the boards tend to rot quickly.

I have a mess of other non-complimentary things to say about the mechanical design of the IC-7000, but I must admit that as long as it's working, it sure is a nice little radio. It's just that it was never designed to be repaired.

I have some more photos if you need them.

Hi Jeff,

Thank you for your experience working on this radio. I have no intention of opening the radio to work on it since I have two other dual band (2M/70CM) transceivers (FM) that put out 35 watts on 440. My only interest is SSB on 440 using this IC-7000.

I received an email from someone regarding the idle current when transmitting without modulation. I will check it with the current meter in line and follow the SM procedure.

If I resolve this issue, I will certainly post an update.

Thanks again, John N3AOF

Hi,

UPDATE:

Well it looks like I have evidence that the problem may be the final amp or associated circuit. In the "Adjustment mode", I checked the idle current (transmit SSB without modulation with a current meter in the power supply line as described in the SM. For HF/50M and 144M against a "00" setting reference (as described in the SM), the current was higher by the specified amount compared to the "00" reference. However, for 430M, the idle current is the same as the "00" reference, and it can not be increase (in transmit) to the value specified in the SM. Rotating the adjustment dial, which shows a change in the number, has no effect on the idle current.

I will not pursue this any further at this time. I am able to use 430 MHZ SSB, but at a lower power level (around 18W).

Thanks to everyone for your useful suggestions.

John N3AOF

Kinda looks like the RD60HUF1 RF output xistor might be toast. The Vgs bias adjustment is a DC characteristic, and does not require any RF drive to function. See Pg 2/7 which shows the Vgs to Igs graph. At Ids=2.5A, Vgs should be 2.5 volts. You can measure that with a volts-guesser by simply removing the bottom cover:

$29.20 from RF Parts.