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Author Topic: Need help with TS-520 tune up  (Read 2676 times)

Posts: 130

« on: January 24, 2013, 06:25:21 PM »

I can't get a dip in  the plate on my 520 when in the tune mode.
Here is what I have: Bias is set at 60ma. ALC/Drive works great. Carrier a little less than "5". Load is set to minimun.

When I switch to ip and flip the switch to send, the meter needle  doesn't move. Turning the Plate knob does nothing.
If I put the Mode switch to CW and flip the send switch I can dip the plate and dial in 225ma or less and adjust with a combination of plate and load knobs.
I set it up as best I could, ignoring the inability to dip the plate in tune mode but set it at about 200ma in cw mode and got on the TN Phone net at 3.980 ssb. Through my dummy load. I forgot to switch back to the dipole! So I guess the signal was getting out.

Anyway, I am wondering if I have a big problem in not showing a dip in Tune/ip or maybe this is a 520 thing. I had a TS-830 years ago but can't recall this problem.

Any info will be appreciated.

Posts: 3289

« Reply #1 on: January 24, 2013, 08:32:38 PM »

You have to tune in CW Mode.  

[edit] Ok, I reviewed the procedure, in Section 4.9.  I don't think that it makes any difference, since the final adjustments are made in CW mode, with the meter in RF mode. 

You might be sure you are getting enough Drive, and dipping the Plate I, in USB/LSB mode just gets you into the ballpark, which you are then going to shift to CW mode, and do final adjustments to it again.  shrug.
« Last Edit: January 24, 2013, 08:44:22 PM by KB4QAA » Logged

Posts: 3160

« Reply #2 on: January 24, 2013, 09:27:04 PM »

Kenwood Hybrid Tune-Up Procedure
by Ken, K4EAA

Here are some instructions for how to properly tune your Kenwood hybrid transmitter.  It takes longer to describe than it does to actually tune the rig!  When you have done it a few times, you can tune up in about 5 seconds total, faster than it took you to read this paragraph!

1. Begin tuning with the Mode Switch in the Tune position.  That reduces the screen voltage, and mis-tuning won't harm the rig.  Start with a dummy load if possible.
2. Set the Load Control to Minimum, and dial in the band (approximately) on the Plate control
3. Set the Meter Switch to ALC
4. Turn the CAR Control (carrier) up 1/2-3/4
5. Place one hand on the Send switch and the other on the Drive control
6. Flip the Send switch and peak the Drive control.  If the meter pegs, turn down the CAR control and peak Drive again.
7. Switch Meter to Ip (plate current)
8. Flip Send switch and tune the Plate tuning to dip the Meter (minimum reading).  This is usually the max power output point as well.
Now you're ready to go for some power!  As you perform the steps below, don't leave the rig in Send more than 5 seconds at a time.  Give it a rest now & again as you get familiar with this.  Most of us can tune a rig in about 5 seconds total, you will too when you've done it a few times!

1. Switch Mode to CW
2. Flip the Send switch and re-dip the Meter with the Plate control
3. Note the Meter reading - You are looking for about 225ma, depending on your power needs - About 1/3 to 1/2 less for PSK or RTTY
4. It will probably be low.  Turn up the Load control about 10 degrees, and re-dip the Plate control.  Continue doing this until you get about 225ma of plate current when dipped.  Remember not to leave the rig in Send too long while you're learning, give it a 5 second rest every 5 seconds.
You're almost finished!  Transmitting at this point would be fine, but you may be able to tune for a bit more power.  The next adjustments should be small adjustments, you are "fine tuning" things at this point.

1. Switch your Meter to RF, or use an external power meter for reference.
2. Tune the Plate control for maximum power output.  You should see about 100W if you have a power meter.  
3. Try adjusting the Load up or down a bit, re-peaking with the Plate tuning after every adjustment.  
4. When you're satisfied with your tune-up, check Ip, the plate current, and make sure you're not too far from the 225ma target, and note the position of the controls to use this as a starting point whenever you return to this band.
5. For CW, use the CAR control, and for SSB, use the MIC control to keep the ALC within the range shown on the Meter.  This will insure maximum power output without excessive compression.
« Last Edit: January 24, 2013, 09:30:24 PM by W9GB » Logged

Posts: 3746

« Reply #3 on: January 29, 2013, 07:02:52 PM »

hi Don,

please join other kenwood ts-5xx and 8xx hybrid fans

73 james

Posts: 9

« Reply #4 on: January 30, 2013, 06:40:29 AM »

If you have no plate current in Tune mode you most likely have lost one or both screen grid divider resistors. Two 56k ohm resistors on the HV Unit board are used to reduce the finals screen grid voltage so that you can get tank tuned to resonance with lower voltage and less stress on the finals. Check R5 and R6 on the HV Unit board. If one is bad replace both.

If you have no experience working inside a Hybrid exercise caution as there are high voltages that can injure or kill you. At minimum make sure line cord is unplugged and HV filter caps are discharged. I would also discharge 210 and 300 on Rectifier board before barehand touching R5 and R6. Terry K9TW
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