Problem with RCA TX1, RCA TX2, RCA TX3 Keying KPA500 Amp

Al Dewey

Had 6600M about a week now.  Tried it with KPA500 amp today.  For some reason, RCA TX1, RCA TX2, and RCA TX3 are not keying.  I have them all enabled on the transmit page.  If I connect the cable directly to the amp and short the cable, the amp keys fine.  I put a VOM on TX1, TX2, and TX3.  They measure about 30 ohms to ground.  Nothing happens when I key the rig.

Any ideas what I might be missing?

73 de Al, K0AD

Jon_KF2E

Try checking out this thread.

https://community.flexradio.com/flexradio/topics/6500-not-keying-ptt-on-elecraft-kpa500-amp

Jon...kf2e

Wayne

Look at the bottom left of the menu/transmit tab where it says RCA and change that setting to Active Low. Also beside the Rca tx# that you are using for the kpa500 change the 0 to 20. The kpa500 is a super amp the best!

Al Dewey

Jon and Wayne - Thanks for suggestions but , unfortunately, neither of them got me going.  Most of the comments on Jon's link have to do with KPA500 and KAT500 wiring.  That is not the problem.  I bypassed the KAT and plugged directly into the amp.  My ICOM keys it OK and, of course, I can short the connectors on the cable and that works too.  But no-go using the TX1, TX2, or TX3 outputs from the Flex.

I did change the delay from 0 to 20 on TX1 and set the RCA Interlock setting to Active Low. Still no luck.

The only thing I didn't try was the pin on the accessory connector but that requires kind of a messy cable.

Any other suggestions?

73,

Al, K0AD

Barry Simpson

Hi Al

My 6600M keys my KPA500 with no problems. Which output RCA socket are you using ? Are you sure yours haven't been mislabeled ? The bottom row are TX1, 2 and 3 and the end one nearest the USB sockets is the 10MHz input.
Have you tried a different RCA to RCA cable ? Are you plugging the cable into the correct RCA socket on the KPA500 ? It is the bottom (red) socket.

Barry  VK2BJ

Barry Simpson

Al

A couple of further questions. How are you keying the 6600M ?  Does it go into transmit ?

Barry  VK2BJ

Wayne

I have no alc enabled when using the amp you may try ensuring the alc is disabled oh and also make sure you can transmit when you key the mic without the amp on. I say this because when I get frustrated trying to make something work I sometimes overlook things like maybe being out of band with frequency.

Also The kpa when in standby will show any power passing through it over 20 watts so set your power at 30 watts make sure the kpa500 is in standby and transmit and you should see the green leds reflect the 30 watts passing thru the amp. And of course when trying to key the amp be sure it is in operate I sometimes forget to press that button on the amp.

On the rig check your transmit interlock as well.

One of the other posts that was having difficulty indicated that when they updated the kpa500 to the latest firmware it solved the issue they was having.

And last if none of the above help the on Monday be sure to get the help desk involved as last resort, of course murphy's law says these things always happen on weekends when flex is closed.

Al Dewey

Yes - I have double checked it is the right TX1 socket on the back of the 6600M.  It is labeled as shown in the User Manual and as you describe above.  Also checked the cable with VOM and it is good.  I am plugged into the correct socket on the KPA500.

Al Dewey

Barry - I am keying the 6600M with keyer paddle.  It does go into transmit.  The TX lights on the radio and I see power on my external SWR meter.

If I unplug the cable from my 6600M and short that end, the KPA does key and goes to full power.  it also detects the frequency of the band the 6600M is on and changes to that band correctly.  For some reason, the 6600M just does not seem to close the TX1 contact on the back of the radio....... de Al, K0AD

Al Dewey

ALC is disabled on the 6600M.  I do see the green LED light on the amp and I do have the amp in OPERATE.  I really don't think it is KPA500 firmware as I can key it fine with my other radio and also  by shorting the cable going into the amp.  On the rig, I have tried all three RCA Interlock settings (including disabled) without success.

Guess I will have to contact Help desk at Flex on Monday.  I will also be at Dayton.

de.....Al, K0AD

Bill -VA3WTB

The help Desk will likely ask you to do a factory re set, this often fixes things that may not be in sink.

K1UO Larry

Hi AL,  Did you, just for kicks, load the enabled TX1,2,3 settings into your default TX profile. Or a TX profile name associated with the Band you are on?

k0eoo

Hi Al, Dennis, k0eoo here,

With the RADIO SETUP open and the TX tab selected, when you put the amp into operate mode do you see the RCA TX port you are using show ENABLED?

Al, I'm local and we could get on the phone if you would like, send my an email at call at arrl.net with your phone number, I'm available this morning to discuss....

Wayne

Im sure also then on your menu /transmit tab the tx inhibit shows disabled and the interlocks accessory also shows disabled... thats all i can think of except i only have rca tx1 enabled and the rest disabled make sure the acc tx is disabled also.

Al Dewey

Dennis and Wayne - Yes, RCA TX1 port is enabled, the rest are disabled, and ACC TC is disabled.  Still no work.  Tried everything suggested so far.  I will contact Help Desk tomorrow.  Thanks.

Bill -VA3WTB

Al you didn't mention anything about doing a factory reset...

Al Dewey

Bill - Is that normally done without talking to Help Desk first?  I agree that this is probably where I am headed. 

AL, K0AD

Bill -VA3WTB

It won't hurt anything Al, it is a last resort if everything you try fails.
Just save you profiles to save you time setting back up

Al Dewey

Bill - Did Factory Reset.  Reconfigured RCA TX1.  Still no luck.  Will contact Help Desk tomorrow.

Al Dewey

In case anyone is following this thread, the problem with RCA TX1. TX2, and TX3 ended up being hardware.  I worked thought the Help Desk at Flex and they send me a replacement radio.  Everything (including TX1, TX2, and TX3) works great on the new radio.  Thanks to Flex for their prompt response!

Bill -VA3WTB

Wow, glad your all fixed up. Next let us know how you make out with your radio, hope you have fun...

Wayne

Thanks for the update Al hope your having a great time.