CW reception fine, all other modes highly attenuated

k3pw

Hi all. I'm looking for some help to resolve a very strange problem. I've had a 6400 for a few months now and have been very pleased with the performance and enjoyed learning all the Flex will do. Yesterday, I finished moving the radio to its permanent location in my basement workshop. I've been using SmartSDR for Mac since setting it up originally next an iMac. I'll still be using the iMac when operation from upstairs but in the basement I have just setup SmartSDR for Windows on a Win10 desktop I built a number of years ago.

This is where it get a bit strange. I connect to the 6400 using the Win10 machine and even though my remote LDG tuner matches the antenna well and is giving a good swr, there are no signals on the panadapter. I tune down to the CW part of 20m, change mode to CW, and signals pop up all across the band - not only the CW signals, but SSB signals further up the band.

Assuming it was something in SmartSDR setup on the Win10 machine, I connected using the iMac upstairs which was previously working fine and got exactly the same behavior - signals look great when the mode is set to CW, but disappear when set to SSB or any other mode other than CW. The behavior is the same on all bands on both computers.

I tried setting the RF Gain at different levels and found that when set on 16db or 24db, the stronger signals start to appear.

Below are two screenshots, one with mode at CW and one at SSB. The change between taking the two shots was changing the mode.

Any help will be greatly appreciated.

Stan, K3PW

k3pw

One additional comment, I rebooted the 6400 but the situation is the same.

Thanks,

Stan, K3PW

KD0RC

Hi Stan,

Do you by any chance have a remote antenna switch in the line being driven by the laptop? I wonder if something like that could be switching to an open port or just the wrong antenna.

73,

Len, KD0RC

K0FLY

Stan:

You said that you rebooted the 6400. Does that mean that you did a "Factory Reset" per the manual or did you turn the radio off and then back on. If the later do the "FACTORY RESET" per the Flex manual. Several weeks ago, I had a similar problem on my 6500, SSDR indicated that It was using antenna port 1 for TX and RX, in actuality the radio was using antenna port 1 for receive and connected to antenna port 2 in transmit, The factory reset straightened it out. I was getting ready to NCS the Iowa SSB net when this occurred. I switched to the second radio for the net. I'm using version 2.6.2 on both of my radios. I have had to reset a radio once since loading 2.6.2

Gayle K0FLY

KD0RC

Another thought... Are you sure that the tuner is not set to the wrong port, perhaps to one with a dummy load attached? This could explain the good Xmit SWR, but no signals on receive.

Len

k3pw

Thanks for the suggestions, Len and Gayle.

I believe I did the factory reset - hold down the power button for 5 seconds or so when when turning on the radio and the button turns from green to white while resetting.

I have a pretty basic setup since I'm just now installing it in it's permanent (??) home. There is only one antenna, 43' vertical, connected and the tuner is an LDG remote tuner installed out at the antenna.

Literally, the two screenshots were a few of seconds apart and the only thing I did between screenshots was change the mode.

David Decoons, wo2x

Can you test from another client? Windows, IOS, etc. In case the Mac client is doing something funny.

Dave wo2x

ka9ees

@k3pw

I don’t know if I can replicate this with my iPad. I have an LDG AT-1000ProII. If power is taken away, no signals pass through it. Grant you we’re comparing apples to oranges. I was just wondering if something like that is happening here.

73,

Ed KA9EES

k3pw

Dave, I’m experiencing the same problem on both a Windows 10 computer and on an iMac using SmartSDR foe Mac.

Ed, The tuner is working fine.

Thanks for your comments.

Stan, K3PW

ka9ees

I'm not saying the tuner isn't working. I'm saying is it somehow being turned off.

Ed KA9EES

k3pw

Ed, Thanks for your comments! The problem comes and goes with the change of mode from SSB to CW and back so that would mean that the power to the tuner would need to be turning off and on with the mode changes. I think that’s unlikely since the power to the tuner comes from the Bias-T, not the radio.

Stan, K3PW

ka9ees

I looked at your type of tuner and that won't happen.

Ed KA9EES