Technical Questions & Answers
For Kenwood Amateur Transceivers TS-520, TS-520S, TS-820, TS-820S, TS-530S, TS-830S, and more!
From the K4EAA Ham Radio Email Logs
PAGE 10
 

Over the years I have received and answered many thousands of technical questions from Ham Radio Operators.  At this juncture, I suspect I have answered every Kenwood question that is possible to ask at least once - And several, many, many times.   While it takes a fair amount of time to add to the FAQ, with pictures and diagrams and the like, the email questions can be copied and pasted reasonably quickly.  That is what I have done here.

I will be adding to these as time permits, as I have over four years worth, after all!   You can either read through the emails page-by-page (like a novel!), or search the site for keywords which will lead you directly to your area of interest.   ENJOY!   Ken, K4EAA


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Well I Followed your directions and I have a great Dummy Load thanks alot! and I have a TS-820s That has the digital display and the radio has to warm up before it comes on, Is this a major problem??? or do I just need to live with it ha ha ?? Alos There is a older gentleman in the group that is wanting to call ya , he doesn't do the computer thing, He has a hybrid radio also that needs attention!
Thanks Butch


Hi Butch;
Congratulations on completing your dummy load! Handy critters to have around.
The DG-1 assy in your TS-820S probably has a bad plated-through hole on one of the boards. Usually, it's the digital counter board. You have to go through and solder a wire through all of the through-holes that don't have part leads in them, and then solder the IC pins top & bottom where they go through plated-through holes. That usually does it!

Great luck, and best 73's,
Ken


I know you are busy, but can you suggest the method to get the driver tube from the shield? I have a new tube, but I can't get the old one out of the shield.
Thanks, Jim

Hi Jim;

Usually I can pry the shield apart a bit with a small, thin screwdriver. If you can spread it open a bit, the tube will just slide out. It should be a loose fit over the new tube, until you slide it over the attached ground strap on the socket. It should just be snug at that point, not real tight - So you can remove it more easily! That ground strap makes much better contact if it's inside the shield.

Hope this helps, Best 73's,
Ken


I have a Kenwood TS-820S radio that was working great. I hooked up a external vfo and speaker tonight and turned it on. Receive is great and vfos both internal/external work great. I went to tune it up on 3916 and hit the send button and NOTHING HAPPENED!! NO Key up, relay or anything. I took the external vfo off and replaced the plug that has to go back into the Kenwood and still NOTHING. I took the covers off and checked for loose connections and tapped around and everything looks fine, but it wont key up. I really want to keep this radio as it has the SSB filter in it, I know quite of few hams run these rigs and could tell me what they think. THE RADIO WONT KEY WITH THE STANDY SWITCH OR MIC!! Never seen this before. The tubes all seem to be lit and the bias switch is in the UP position.. I appreciate any and all suggestions.
Thank you
73 Kenny


Hi Kenny;

If you're not hearing the relays pull in, it sounds like a broken connection to the Send/PTT wiring. If it lights up, receives, etc., the voltages are present, that leaves either 2 bad relays (rather doubtful) or a missing connection.

Let me know how it turns out. Best 73's,
Ken



Ken,

I have kind of a weird question. I find myself working more and more QRP, but I really enjoy the 830s. How feasible would it be to modify an 830S to put out a max of 5 to 10 watts, or even 5 watt max? Is this something you could do? Something I could do? Not possible?

Many thanks,

Steve


Hi Steve;

Turn the LOAD control fully counterclockwise and dip the plate, that should get you down to around 25W, give or take - Then you can use the MIC or CAR control to inch it down further. Another way is to hook a pot up the the ALC line on the rear panel, designed to be used by linears, and dialing down your drive/power from there.

A more permanent solution would be to reduce the screen voltage to the finals. In TUNE position, a 50% divider (two 56K resistors) are used to limit the output power. If you replaced the 470 Ohm resistor is series with the screens to a higher value and added another resistor to ground forming a divider (i.e. like the TUNE divider), you could set up whatever maximum output power you liked. That mod is not very intrusive, and could be easily reversed.

I hope this helps, best 73's,
Ken


Ken,

Hey, thanks! Rig is working great! Ken, If I dip the LOAD, and go lower with CAR, (I just operate CW), will that damage the rig at all? Shorten the tube life?? That seems the easiest way to go.
Thanks agn,
Steve

If anything, it should extend the tube life - Everything is running cooler and just coasting along.
73's, Ken


Hi Ken, Just looking over your FAQ's I've heard of people bathing boards and even using dishwashers and ovens to dry. I don't think I would go there, but a simple soapy bath like you show I've been trying to work up the nerve to try. I'm surprised you don't have a problem with water being trapped in the cans and coils even after a thorough drying. I just got another TS830 and this one belonged to a heavy smoker. The cabinet, knobs and face plate removed and washed came out like new. My question is are there any boards or areas you would not wash. I'm tempted to remove all boards one by one and give them a bath. The 830 looks great on the outside now, but that rear cooling fan keeps reminding me how bad it smells and how it looks inside.
thanks, Dave


Hi Dave;

I'd keep away from the VFO unless you removed the board and washed it separately, but everything else is fair game. Modern electronics mfrs all use water based washes for their boards. I've seen Ham restorers take rigs (Collins, Johnson, Kenwood etc.) into the driveway, suds them up and hose them off. There is nothing in a Kenwood that is affected by water. Just dry it well and lube everything afterwards.

73's, Ken


Hi Ken,

I noticed that the S meter has stopped working on my TS 820s. The meter seems to work for everything except the receive signal strength. I have a habit of turning my RF gain control up until I no longer hear the band noise; that has always caused my s meter to go to 1.5 or 2 units on the S meter, then when a signal was present the S meter would moved up scale. Now the meter is just flat, (no fluctuation when signal is received & no movement when RF gain is adjusted). Is this a command problem and is the do it yourself remedy? The meter works for all other functions.
If you can give me any guidance on this problem it would be greatly
appreciated.
Thanks 73 Casey


Hi Casey;

It could be dirty contacts in the T/R relay located near the AF board on the underside of the radio. It could also just be dirty trim pots in the S-Meter amp. There are 2 of them, and they are located on the IF board. There is a 2-transistor meter amp for the S-Meter that could have a bad part, but I'd guess it's just one of the pots. Spray them and work them back and forth, and then set the zero position first, and use the calibrator at 14.175 with everything peaked to set S-9 with the span adjustment. That will probably fix the problem.

Hope this helps, 73's,
Ken



Ken,

I'd like to hear the short-n-sweet on 6146W tubes - better and recommended over 6146B tubes for 520 and 520s rigs?
The manual says matched tubes aren't important - they only need neutralizing. Any insight?
Thanks in advance for your time.
Sincerely, Larry


Hi Larry;

The W's have slightly lower output and purportedly longer life than the B's. I have used both, not enough difference to really matter.

The finals don't have to be matched, but should be the same mfr and type and built about the same time. Kenwood runs the finals very conservatively and a small mismatch in gm or idling current is not that important. I've seen rigs come in with mixed A's and B's made decades apart, and they still safely produce 100W! I definitely do not recommend that, however!

Hope this helps, 73's,
Ken


Ken, I performed the band-switch repair as outlined on your web page. My TS-830 was intermittent on all bands (RX) when I started. Moving the bandswitch would bring the RX up and down by 20 to 30 dB. The bandswitch repair was easy to do based on your instructions. I took a lot of care and obtained the circuit writer pen as you had suggested in an earlier email. Once reassembled my rig is working great on all bands except 10MHZ, 7mhz AND 3.5 mhz. These three bands are dead on RX. and I haven't tried TX. (this may have been a previous problem)
Before I go back and disassemble the RF board again can you suggest a common fault that might be causing just these three bands to be dead.
Thanks for your help....73s Fred.


Hi Fred;

When only some bands are affected, it has to be the bandswitch and/or related parts - Coils, caps, etc. on the RF board. The rest of the circuitry is used essentially on ALL bands, so if one band had a problem, they'd all have problems. That is the good and bad news - You know where the problem lies, but it's hard to get at!

One common problem in using the silver ink pens is to get the ink too close to the spacers between the wafers - This will short those contacts to ground when reassembled. Take it apart, all looks great - Put it back together, and shorts everywhere!

You might check if any ink is pinched under the spacers - That would be my first guess. It can be scratched back with an Exacto knife.

Hope this helps, 73's,
Ken


That's a good place to look. I never would have looked for a short to the long screws....
Oh well, I'm getting good at taking the board in and out...Thanks for your help... I'll let you know what I find.
73's Fred.


ken,
it was a solder splash that shorted one of the pins on one switch deck to ground. (Probably from the solder sucker)
All bands working great now.
I noticed the audio is a bit distorted on strong signals. Is this typical of this radio ?
In any case thanks for the assistance on this repair..Your web page was very helpful.
I will spend a few hours reviewing your site tonight to see if I need to do anything else before I put the covers on the
old rig. I'm getting 75 watts out on 10 meters CW with the original finals...Can't wait to get it on the air next weekend for Field day

73s Fred.


Hi Ken,

I built the 50 ohm dummy load using the LK-R1 kit, filled the can up with mineral oil, measured the resistance at the output, resistance measured 49.9 ohms. Checked it out statically by applying 30vdc to the SO-239 connector. Current drawn from the dc source at 30vdc measured 600 ma, which worked out to 18 watts. I kept power on the dummy load for one hour and to my surprise the top 1/3 of the can was very hot to the touch. I would have thought that the 20 three watt resistors immerged in mineral oil should have been able to dissipate evenly 18 watts without generating that amount of heat.
I would have expected the can to be slightly warm. I have not yet connected the dummy load to my heathkit DX-60, because I am in the process of restoring the transmitter. The resistors should without any problem be able to handle at least 60 watts submerged in mineral oil.
What are your thoughts in this regard.
73,  August


Hi August;

Sounds pretty normal. 18 watts dissipated in a quart volume for an hour should get things hot to the touch. The resistors will dissipate 60W in free air, and submerged in oil, 120W easily for several minutes. Where do you expect the heat to go? 8^)

Hundreds of these are in use, no problems reported over the last 3 years.

Best 73's,
Ken


Hi Ken,
Thanks for the information, you designed a great unit.
73, August


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