6600M 3.2.39 Reboots when tuning a high SWR antenna

N1SH

I have a pre-loved 6600M and it works mostly fantastic. I was poking around yesterday and tried to tune up on 10m with an old OPEK-HVT stick. The stick is set for "10m" but has always been quirky with strange high SWR readings in any setting. When I hit the ATU, I get a few clicks and then the panel reboots and I get a red flashing light. If I hit the power button, things restart and start up normal.

I have RF Power at 10 and Tune power at 5.

What gives? Is this normal? Am I doing something wrong?

Ha Gei

I suspect RF coming back into the machine over the cable during tune. In our case we see such habit , not at the flex, but we can easily drive the network switch bananas with such...

KD0RC

@N1SH What is the blinking pattern of the red power light?

From the FLEX-6400 / FLEX-6600 HARDWARE REFERENCE:

Error Conditions

Certain hardware and software error conditions cause the radio to stop operating and display an error code by flashing the Power button light as follows:

• One red flash: Fan malfunction

• Two red flashes: Software crash

• Three red flashes: Boot failure

• Four red flashes: Input power over voltage

• Five red flashes: CPU overcurrent

• Six red flashes: Input power under voltage

In the case of a software crash, the error code repeats for about 15 seconds, then the radio will reboot. In the other cases, the error code repeats until the Power button is pressed, then the radio shuts down. An additional press of the Power button is needed to restart the radio

N1SH

Update: Same thing happens without the ATU using an external manual antenna tuner and a reported SWR of ~1.3 when transmitting with RF Power of 5.

N1SH

Waiting for it to do it again so I can read the red blink code. Thought it was one flash, but want to be sure.

KD0RC

Right... But what is the flashing pattern of the power light? That will tell you very directly what is happening.

N1SH

Definitely one repeating red flash until I hit the power button. The fan does run briefly when I turn the radio on, but then turns itself off. Sounds like a helpdesk ticket is in order :-(

KD0RC

Yep, most likely a fan or possibly an SD card issue. I would put in the help desk ticket and see what they say. How old is your 66ooM?

N1SH

NOTE: I can feel air coming out the back of the unit while it's just receiving. Not the high speed I hear when the unit starts, but there is a fan in there working away somewhere.

N1SH

Len, it's a pre-loved one, but I've only had it about 2-3 months.

KD0RC

Here is some info published by Tim about fan issues that might help:

https://helpdesk.flexradio.com/hc/en-us/articles/360036859212-Resolving-the-single-red-blink-Fan-Error-on-Start-Up

Mike-VA3MW

About 100% of the time, when this happens the radio browns out and reboots as the power monitor senses that the DC Voltage has dropped below 11 volts.

The next test is to run it on a dummy load to see if it is an RF issue, even at 10 watts. If it fails, it is a voltage supply issue. If it doesn't fail, it is an RFI issue.

I would also try another RF jumper cable. If it is possibly compromised.

You should add a 100 watt dummy load to your tool kit if you don't have one.

If, after all that you still have an issue (good cable, good power and good dummy load), then I recommend opening a support ticket.

73

N1SH

Looking like the single red blink being a fan problem is a red herring.

Running into a dummy load presents no problems up to 100W. Voltage is also stable (at the radio) all the way. Needing to take a closer look at the antenna. It's not shorted or anything. I guess it could have internal problems somehow. A different one is on-order, perhaps this one is destined for the recycle bin.

Not sure it will persist outside of this small thread but the Hardware Reference clearly says, one red blink is a fan problem, and it's not always that. Perhaps it should/could be updated. The response to the helpdesk ticket was/is along the same lines, diagnosing power and/or RF problems.

Harold Rosee

I had this happen when I was on the wrong antenna the other day. SWR was way high on 6 meters and RF got into my power supply.

Since it's working well on a dummy load you might want to put some chokes on the power supplu A/C and D/C leads. It's sure worth a try especially if you are using a switching supply.

Harold

W5ZZT

John KB4DU

Though not specifically documented, I have had the single red flash when the computer gags on something and loses the connection to the radio. Had a warranty replacement on the fan, but that was not the problem.

HCampbell WB4IVF

Since the problem does not occur with a dummy load, and you are using a base-loaded mobile whip, I suspect RF. Your whip acts like half of a dipole, and the transmitted RF is searching for the other half, or a counterpoise to replace the other half. If you don’t have a good counterpoise, the transmitted RF will try to make one out of the feedline, your radio, and/or other connected gear. Where is the antenna mounted and what is the counterpoise (vehicle, radials, etc.)? Before sending the antenna back, I’d check out the feedline/connections and make sure you have a good well-connected counterpoise.

Good luck!

Howard

Erik Carling EI4KF

Just my experience with a new 6400M (connected to a computer, the 6600M owner does not state whether his is similarly connected or standalone): I was getting a few clicks and then panel reboots with a red flashing light. This was on 20M with 40W to an Ultrabeam dynamic antenna on a 40 foot mast with no SWR issue. The culprit was the ethernet cable. I replaced it with a screened cable. Now all ok up to my license limit of 1500W.

N1SH

**Resolved**

Transmitting into a multi-band (80-10) end-fed half wave with a with an RF Isolator in-line works without any resetting. So I'm calling it resolved as a bad antenna or bad connection on the ground plane with that antenna.

As noted above, the single red blink sends you in the wrong direction. The radio and the hardware reference could be a little better on this front.

(a) I understand the back-end radio shutting itself down and/or disconnecting to prevent burning up the radio, but why does the Maestro front-end reboot as well?

(b) The hardware reference should indicate that the single red blink may indicate other errors, like common mode RF.

For the record and future readers, the Ethernet cable is a new Cat6 fully shielded (metal shield on RJ45 connector) cable.

Mike-VA3MW

EFHW antennas still require the feedline to be part of the antenna. The RF still has to be delt with a couterpoise and RF chokes in the right place. This is why the RF Isolator is there (you can't change physics).

The Maestro rebooted as you possibly had RF getting into the DC power cable on the Maestro or some other cable that was connected to the Maestro. Every wire we own is also an antenna even though that doesn't want we want it to do.

There really is no way to detect the symptom your report, common-mode RF. The power controller reported an issue with the flashing RED, but the cause, as you saw, can be totally different.

It is like saying your car says you have a flat tire. It can't tell you if there is a nail in the tire, a bad valve or a leaking seal on the rim. The symptom is the Flat. You can pump up the tire again, but it will go Flat again. You haven't fixed the Symptom, which is to repair the leak. :)

73

John KB4DU

Right, a single red flash can be caused by several things, not just a fan issue.