6600 Won't Connect Directly

Frank Kirschner

Trying to trouble-shoot a problem (computer/rig locks up when I transmit more than 80 watts on 160 or 80). I thought I would eliminate the gigabit switch first. I connected the 6600 directly to the Ethernet port on the computer. I get an error: Unable to connect to the radio. Please try again.

Other than locking up on two bands, connection through the switch works fine. (This is a new problem that started when I had to modify the antenna so the new Palstar HF-AUTO could tune on 40 meters.)

Relatively new Flex 6600
Win 7 64, SSDR 2.4.9
I7 at 3.9 GHz, 16 GB RAM

Any ideas on either of the two problems?

George KF2T

George KF2T

Joe N3HEE

Joe N3HEE

You don't need a crossover cable.  The radio detects the direct connection and switches the ethernet interface accordingly.

N9VC

George KF2T

Thanks for the correction, Joe!

Frank Kirschner

All,

Thanks for the suggestions. I have all but one covered: the distance between the antenna and the computer. The antenna in question is a random length (about 82 feet, determined by the height of and distance to a line of trees behind my house) sloping, mostly-vertical which starts about three feet from the rig and computer. I set it up that way because I had already laid out the radials starting from the ground rod next to the house.

I had been using an MFJ-998 autotuner, but got the Palstar so I'd have more overhead with the Alpha 87A amp. It wouldn't tune 40 meters, so I added 44 inches of length to the antenna itself, and about six feet of coax with a dozen ferrites. It now tunes 160 to 30 with no trouble. (20 to 10 goes to the TH-11 up 65 feet.) The problem crops up only on 160 and 80.

I'll try more ferrites and a few ground straps on the computer itself. It would be a significant undertaking to move the computer elsewhere due to the three monitors and serial cable to the Alpha, but I may have to try that next.

73,
Frank
KF6E

Rich McCabe

Frank Kirschner

I hadn't thought of that. I'll check. Thanks.

Joe N3HEE

Frank, I assume everything was fine before the antenna mod.  No RFI issues ?  Need to back track your steps to see what is wrong.  It's better to find the real issue than trying to fix it with ferrite beads and ground straps.  That thing is going to go nuts when you turn your amp on.  I'm guessing all was good with the MFJ tuner ?  Can you bypass the HF Auto and tune the antenna with the 6600 internal antenna tuner ?  If so do you get RFI issues on 160 and 80 meters.  What end of the random wire did you add 44 inches to ?  How and where did you add 6 feet of coax ?  Splice or barrel connector ?  Also do you own or have access to an antenna analyzer ?  That will answer questions about reactances and feed point impedance's.  Sorry for asking more questions than answering.  Just trying to troubleshoot this issue in a systematic way.

Frank Kirschner

Mark WS7M

Hi Joe,

Just to add to the RFI thing:

I had a roughly 280 foot loop up for a long time.  No RFI at all ever. 

I replaced the 14ga wire in that loop with 12ga wire.  It was way to long and resonance was at like 6.4Mhz instead of the roughly 7.050 I wanted.

So I spent a day snipping away and retesting with my RigExpert until I had the loop at roughly 1:1 on 7.060.

Reconnected everything and now at high power (1500) I have RFI on audio.  Go figure...

So pretty much ANY change to your setup can trigger an RFI issue even if your antenna is good.  Sometimes you just have to futz with things until you find the culprit and it goes away.

Joe N3HEE

Frank Kirschner

Frank Kirschner

The extra coax was suggested by Palstar. They thought that moving to a different position on the Smith chart would make it easier for the HF-AUTO to tune. I have since taken that out.

I went through the exercise of looking at the complex impedance on the four bands I use that antenna for, and it didn't look good. Many frequencies had R=0 or some other very low amount. Nonetheless, the Palstar does, in fact, tune on 160 through 30. It balked only on 40, and that was in the auto mode. So I went through the entire band and tuned every 9 KHz manually, saving the settings at each frequency. Now it seems to tune fine, with occasional problems. I suspect it's the algorithm that Palstar uses. It changes the L and C in whatever direction lowers the SWR. However, the tuner may be in a configuration that requires going over a "****" in the SWR to get to the lowest level. The MFJ never had that problem.

My MFJ-998 is back in Mississippi for repairs. I may replace the Palstar with the MFJ when it returns to see if things go back to normal.

Thanks.

Arvind Mallya

Joe N3HEE

Frank Kirschner