5000a is not showing output when transmitting...

Larry Scantlan

Well, I received my microphone adapter so I can hook up my Heil headset.  I attached my foot switch and it appears to be working…at least it’s switching the radio to transmit mode properly.  I have watched the first 19 YouTube videos from KE9NS and am overwhelmed with all the features KE9NS has upgraded PowerSDR with.  I’ve been playing with the receive functions and getting acquainted with the filtering, mapping and spotting functions.

 I have two antennas, an all band, no trap 43’ vertical and a 10-40 endfed dipole.  Both of these antennas have been working well with my Kenwood TS-2000.  The internal antenna tuner in the TS-2000 has been able to match both very nicely.  Unfortunately, I’m experiencing issues with the 5000a ATU.  I cannot seem to match the vertical on 20m.  It says it cannot bring the SWR down.  It does match on 40m but the SWR meter still shows a very high SWR (25.1:0) and as a result the output registers 0 Watts.  The scope shows that it is transmitting but the wattmeter does not register.  I’ve got a Diamond SX-100 inline and when I first key down it registers 100 watts output but almost immediately drops to around 10 watts.  What am I doing wrong?  I’ve tried to responding to a calling station without success as well as calling CQ and the same negative response.  I don’t want to damage the finals in this radio.  Were you experiencing this before you sent the radio to me?  I’ve tried different drive levels including full output and the result is always the same…no output.  I’ve even noticed on my power supply (Astron PS-35M) that the amperage peaks to around 20 amps when I first key down and then drops down to under 10 amps almost immediately.

I’m hoping someone can provide some help with this.  Everything else seems to be functioning as it should.

73,

Larry, KEØKZ

 

Greg N8GD

With anything more than about a 3:1 SWR, most radios will fold back their power to protect their finals. At 25:1 their will be essentially no output as you are seeing. One thing I would check is the cabling to your 500a. Is it exactly the same as you had with your TS-2000, ever right up to the connector on the radio? If there is even one jumper or perhaps an antenna switch that’s different, they may be suspect (open or shorted). Also, if the cabling is exactly the same, sometimes shortening or lengthening the cable to the 5000a may change the matching that the tuner sees (you’re essentially changing the SWR node or minimum point that the radio sees). Also, are you keying the radio in other that SSB mode? You need a constant carrier mode like RTTY, AM, or FM to get a steady output. SSB only works when audio is picked up by the microphone. Just some thoughts on your problems.

Larry Scantlan

Thanks for the comments and suggestions.  Actually, the antenna is being connected directly to the 5000a and not through the RFI filter, Power/SWR meter and MFJ-998 antenna tuner that is in line with my TS-2000.  I have not read much of the operating manual for the 5000a but I'm guessing that when you place the radio in the TUNE mode, it is keying it in a carrier mode such as CW.  My real concern is that the PowerSDR software is reporting a condition which may not actually exist.  The ATU reports that it has correctly matched the antenna to a 1.1:0 condition in 40m and sometimes in 20m but the meter in SWR mode still reports a much higher result and in power mode shows 0 watts out.  I did make about a dozen contacts this morning on both 20m and 40m successfully without the other stations reporting any negative audio or signal reports.  So, not sure what to think.

John

If you can tx into a 50R load ok with a pwr meter inline to confirm output on all bands, then its probably a cable or switch issue somewhere in the system. I would run the vertical cable straight into the 5000 and try the internal ATU, if no go, then disable the internal atu and try an external one. If you bypass all the inter connections, you may well be able to match the antenna. As with all ATU'S, they will only match what they are designed to match and no further. Having a lot of switches and cables can push the atu into the red zone. You may well find that you have a loose connection perhaps on one of the coaxial plugs somewhere. Its a case of illimination to find the problem, if there is one.

Greg N8GD

Larry, You probably should submit a help desk ticket on this, but they are currently swamped with Windows 10 update issues, so it may take awhile for them to get back with you. I’m not a 5000a owner and have never operated one, but I recall that resetting or deleting a particular configuration file in PSDR may solve your issue. The 5000a runs everything in Windows, so corruption of the PSDR software could be an issue if you’re getting differences between what the software reports and what your external metering is telling you. Good luck on resolving your problem.

Larry Scantlan

Greg, 

Thanks for the comments and suggestions.  I have indeed filed a help desk ticket with Flex and have received a response already.  They asked for some specific data from tests done internally with PowerSDR which I have provided and awaiting their reply.  Having spent over 30 years in the IT industry I am somewhat familiar with all the wonderful "incapabilities & issues" Windows creates with 3rd party software.

HCampbell WB4IVF

What John said – a feedline or connector issue would be my first guess.  You might also try adding a few feet of coax.  Sometimes ATUs have a problem matching certain impedances presented to them, and changing the length of the feedline can make a difference.

Howard

Tim - W4TME

As Larry indicated, this issue was being handled via the HelpDesk because it appeared to be a hardware problem.  And that was the diagnosis.  The SWR bridge is inoperable and without the radio getting valid SWR data, the ATU will not work properly.  There were also some power output issues on some bands too.