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Author Topic: Elmering/troubleshooting TS-590sg: Where did the TX pwr go?  (Read 4690 times)

4X1LM

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Hello.
accidentally, I connected the wrong antenna to my TS-590SG.
Since then, the TX power output is proportional the the band!!! The higher the frequency, so is the power, and the best is on the 10 meter band and its only 10 watts!!! ATU is disconnected.

SWR is good.
The power of the 6 meters band is OK.
Full Reset didn't solve the problem.
Power Supply is good too.
 73
4X1LM
Mike
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K8AXW

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RE: Elmering/troubleshooting TS-590sg: Where did the TX pwr go?
« Reply #1 on: May 03, 2018, 11:24:07 AM »

Can you feel the final transistors to see if one is cold?
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4X1LM

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RE: Elmering/troubleshooting TS-590sg: Where did the TX pwr go?
« Reply #2 on: May 03, 2018, 01:24:50 PM »

Both power transistors are at the same temp. The same power transistors are the output of the 6 meters, and on this band the power good.

73
Mike
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NO2A

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RE: Elmering/troubleshooting TS-590sg: Where did the TX pwr go?
« Reply #3 on: May 03, 2018, 07:54:30 PM »

Have you checked the power output into a dummy load on all bands? It's pretty hard to damage a modern solid state radio by accidentally transmitting into the wrong antenna.  [/b]
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KA5IPF

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RE: Elmering/troubleshooting TS-590sg: Where did the TX pwr go?
« Reply #4 on: May 03, 2018, 08:11:38 PM »

Is the ALC showing full scale with the 10w out? If so the radio is shutting down to protect itself.
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4X1LM

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RE: Elmering/troubleshooting TS-590sg: Where did the TX pwr go?
« Reply #5 on: May 03, 2018, 10:04:39 PM »

Thank you.
All test are done while the radio is connected to a dummy load.
On the 10 watts ( 10 meters band) the power is steady and no SWR or high ALC indications at all.
ATU is bypassed.
 73
4X1LM
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4X1LM

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RE: Elmering/troubleshooting TS-590sg: Where did the TX pwr go?
« Reply #6 on: May 04, 2018, 05:29:28 AM »

Hello.
May be this is  some beneficial info.
The Push-Pull output power Transformer is getting hot in a inverse proportion to the frequency, so my assumption is that this due to some  RF mismatch. Can it be the transformer itself??

Thank again
Mike
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NZ4ZN

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RE: Elmering/troubleshooting TS-590sg: Where did the TX pwr go?
« Reply #7 on: May 04, 2018, 05:35:00 AM »

Is it possible you are trying to measure power in SSB, while the 6m band selection may switch modulation to FM?
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4X1LM

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RE: Elmering/troubleshooting TS-590sg: Where did the TX pwr go?
« Reply #8 on: May 04, 2018, 07:59:26 AM »

All power measurements are in CW mode. Something is overloading the power transistors. There is some kind frequency dependent load/short circuit.
Mike
4x1lm
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K4JJL

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RE: Elmering/troubleshooting TS-590sg: Where did the TX pwr go?
« Reply #9 on: May 04, 2018, 11:45:53 AM »

Is your internal tuner on or off?  Sometimes if it gets really high SWR, the tuner will kick out, folding back your power.  It may be on/off memorized based on currently selected band, too.
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KA5IPF

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RE: Elmering/troubleshooting TS-590sg: Where did the TX pwr go?
« Reply #10 on: May 04, 2018, 01:03:37 PM »

If the radio is drawing over 10A in Tx you most likely have a stuck relay in the LPF section. Check and make sure onone set is turned on at a time. If you spend a lot of time on the upper bands start with them. If 10m is Ok then try 12m if low power on 12m out probably a stuck 10m relay.
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4X1LM

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RE: Elmering/troubleshooting TS-590sg: Where did the TX pwr go?
« Reply #11 on: May 04, 2018, 02:53:01 PM »

Thank you all again.
The highest output is on 6 meters- 50 watts. Then the  output power drops when I move to the lower bands. The lower the band so is the power, and the matching transformer becomes hotter and hotter. Maybe even putting out some smoke !!!!
I am reluctant to start unsoldering all the relays.

73
 mike
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KA5IPF

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RE: Elmering/troubleshooting TS-590sg: Where did the TX pwr go?
« Reply #12 on: May 04, 2018, 07:58:42 PM »

Does the current draw go up or down with the power drop???
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4X1LM

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RE: Elmering/troubleshooting TS-590sg: Where did the TX pwr go?
« Reply #13 on: May 05, 2018, 09:07:57 AM »

To those patient people who didn't give up yet trying to help :)
Just to make things simpler, I decided to bypass the filter bank and to connect the power meter directly to the output impedance matching power  transformer, and draw a comparison table between the PS current and the CW output power:
band  current  power (W)
  1.8     5.5       0
  3.5     3.6       0
   7       3.6      20
  14      4.3      22
  21      7.2      30
  24      8.5      50
  28     11.0     45
  50      13.3    100

by the way: where can I buy such output transformer?

Thank you and have a nice weekend
mike
4X1LM
 
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4X1LM

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RE: Elmering/troubleshooting TS-590sg: Where did the TX pwr go?
« Reply #14 on: May 05, 2018, 09:17:51 AM »

More info: after TX on for 5 minutes, the output transistors are just a little bit warm, but the output transformer is very hot, untouchable! just a reminder: the filters are bypassed and the transformer is connected directly to a dummy load with power meter.

Thanks again
Mike
 4X1LM
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