Trouble with TS520S

[W9PSK]

I have been having issues with learning how to tune this rig. Right now I am at the part in the process where I am plate tuning. I've done everything the manual says to do-Meter set to IP, mode set to TUN. When I flip the SEND switch, the needle moves to right about where the 100 is on the meter (the top arched line). Turning the Plate knob does nothing to change this setting. According to the manual, turning the Plate knob is supposed to adjust this setting--it calls for a minimum meter reading. I have done everything the manual says to do prior to this step-Drive Tuning, Plate Idling Current, the initial switch settings in Table 2, the receiver tuning, etc. Is the problem I am having an indication that there is something wrong with the tubes?

I have to be honest. I am starting to lose my patience with this radio. If I skip this step and complete all the others, the radio puts out about 50 watts CW, but then very little power out on LSB or USB. I am trying to give this tube radio thing a fair shake, but I am just about to the point of chucking this thing into the Ohio. "Shall We Gather At The River" is fixin to take on a new meaning.

[N9FE]

Fred could explain better here. I could tell you over the phone. Your close. Don't give up. Don't use the send switch as it key's to long. It don't take much to burn up the final tube. Only use the mic for like a quick three count

[N9FE]

Ya see i learned this at 14 years old. I can't type for chit and explain it all. You'll get the hang..

[WØTKX]

Do you have a dummy load to use as you are figuring this out?

The Kenwood hybrids are pretty forgiving, but eliminating the antenna while learning is a good idea.

This page is very clear... http://www.k4eaa.com/tune-up.htm

[N8YX]

Best way I've found to tune a tube hybrid:

1) Make sure that the idling plate current (no drive applied) is set to 60ma, per Kenwood's spec. Adjust it if not, per the operator's manual. Preset the Plate control so that the indicator is within the band you wish to operate, and the Load control is at 10 o'clock (160-40M) or 12 o'clock (20-10m). These are "preliminary" tuning points, by the way.

2) Peak the "Drive" control on one of the marker signals or on band noise

3) Switch to dummy load; place meter switch in IP position. Place mode switch in CW.

4) Rotate Carrier control fully CCW. With some form of key connected to the CW jack at the rear of the radio, key the rig and advance the Carrier control CW until the IP meter just begins to move upward from its idle point. Now quickly peak the Drive control for maximum IP reading then unkey the radio for a few seconds.

5) Key rig; adjust Carrier control so that IP is 150ma or so. Unkey rig.

6) Key rig, adjust Plate control for a pronounced dip. Unkey rig.

7) Set meter switch to PO. Key rig. Alternatively adjust the Load and Plate controls for maximum PO meter deflection. A couple times with each control is all that's necessary, and you should limit your tune-up time to 10 seconds or less. (This goes for ANY part of the process, by the way.)

8 ) Set meter switch to IP. Key rig; adjust Carrier control for an IP of 200ma then quickly dip Plate control. Unkey rig, wait a few seconds then key rig and advance Carrier control until you see a reading of 200ma on the meter. At this point you should be seeing 100-110w out from the rig into a 50-ohm load. Unkey rig.

9) If running SSB, set the rig to USB or LSB and the meter switch to ALC. Then adjust the Mic control until the needle deflects roughly halfway into the ALC region but not further.

10) If running CW, keep the Carrrier control set for no more than 200ma IP. You can use the Carrier control (or the Mic control) to reduce power as needed.

11) Should you make a minor frequency excursion, you'll need to re-peak the Drive control but usually nothing else. On the other hand - if you make a major (> 100KHz on 20 and up; 50KHz on 160-40) frequency change you'll probably need to go through the whole process anew.

Tuning a hybrid isn't as hard as it seems. In fact, it took far longer to compose this response that it'll take you to set your '520 up on the air!

[N9FE]

Thanks fred. Yep Peak drive first. Then go from there. I just did not want him hanging with the send switch. Make shure you turn the heaters on for 5 mins or so. A good forward reflected meter helps too.. Right.. I can't type for shiet.. One finger ya know.

[N8YX]

On the 'Zed thread (same topic), Ed (HTW) advises to set the Load control at full CCW then proceed to dip Plate/switch meter/peak Load/switch meter/dip Plate, etc.

Oddly, enough, Yaesu states to preset the Load control on their hybrids (specifically, the 901/902 and 101ZD) to a position which approximates on a per-band basis the final required output capacitance.

Keep in mind that the Kenwood and Yaesu PA circuits bear a very close resemblance to each other. Yaesu runs around 750VDC on the tube plates while Kenwood's HV supply is ~850VDC.

In light of the above, it's interesting to see the two companies recommend totally different tune-up procedures - and the balance of their design methodologies reflect this as well. While Kenwood incorporated a "Tune" position on their Mode switches, Yaesu incorporated a tune-up timer and circuitry which allowed for full-carrier tuning in ANY mode, including SSB. Kenwood's design reduced the screen voltage on its 6146 tubes (and with it, overall power output) when in "Tune", thereby safeguarding the rig from extended tune-up sessions by the neophyte. Yaesu limited the operator to 10 seconds key-down in an attempt to do same.

Which approach is better? Hard to say...but I'm eventually going to modify my TS-820S rigs for AM transmission when the Mode switch is in the 'Tune' position. Restoration of full screen voltage by changing some resistor values then enabling the speech amp and directly modulating the RF Amp pre-driver stage are all that's required. I never use the 'Tune' position, preferring to set mine up while in CW mode. If you're quick with the process, you have nothing to worry about.

[N4VGB]

You might want to consider joining this yahoo group/email reflector: mailto:TS-520_820_530_830-subscribe@yahoogroups.com

Lots of help there from some long time dedicated Kenwood users.

[Vinnie]

put a dummy load on it. Problem may well be bad antenna impedance that the 520 can't match to.

Second, have a SWR/wattmeter in line.

Third, peak drive control for max receiver noise.

Fourth, go key down on CW, and QUICKLY dip the finals.

Fifth, tune while looking at the WATTMETER, for maximum output. Keep working the tune and load controls to do this.

Sixth, peak up the drive control You should get at least 85 watts output.

But, I gotta tell you, the TS-520 is not a very good radio. The TS-830 (with aftermarket filters) was/is much superior....I worked well over 300 countries with one of them.

If the above works and the radio tunes correctly into the dummy load, check ur antenna/feedline carefully.

[W9PSK]

Damn, I feel like a heel. I started this thread over here too, some of you took the time to respond, and I plum forgot that I had started it. Sorry about that. I got the 520 figured out and been using it. I really like that radio, much to my surprise. I even got used to the analog dial it has! LOL! In a way, it kinda makes tuning into a signal easier.