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Author Topic: Kenwood ts440s power  (Read 2046 times)

Posts: 3

« on: January 15, 2013, 05:25:53 AM »

I have the kenwood ts440s/at and I heard it goes down to 10 how could I do that and if it only goes down to 15 if I turn down the mic gain to get to 10 from 15

Posts: 3651

« Reply #1 on: January 15, 2013, 08:24:29 AM »

I'm apologize for my stupidity...... but would you mind phrasing that question another way?  As it is, it doesn't make any sense at all.

Posts: 175

« Reply #2 on: January 15, 2013, 03:21:12 PM »

I think I understand what he's getting at...

There may have been a 10 watt version of the TS-440 made for the Japanese domestic market... but...

Unfortunately, in all other markets, the 100 watt TS-440S has no RF power output control; in order to reduce the SSB power output, one must use the microphone gain control to reduce drive to the finals, and it's really a crap shoot at lower drive levels, as there is no limiting ALC action.

There is one trick that I've seen discussed to reduce the output power, and that entails the use of a battery and pot wired up to the ALC input on the ACC jack.  There is some risk in doing this, however; I've recently seen a post, either on here or the Z, of someone having technical difficulty after trying this scheme.  I have no experience with this modification.

An attenuator might be constructed or purchased that can lower the power output from 15 watts to 10 watts.

On the other hand, I don't think anyone on the outside would notice the difference between 10 watts and 15 watts output....  know what I mean?   Wink

Posts: 3

« Reply #3 on: January 20, 2013, 05:18:40 AM »

Thanks VE7DX for the information i will have another go at lowering the power and i recently found a way to do it apperently there is a filter box with a switch on it  if i flip it it will go to 10 to 15 watts or thats what i seen anyway i dont know if that works but i could try both ways

Posts: 3

« Reply #4 on: January 20, 2013, 05:20:13 AM »

sorry VE7DQ

Posts: 13019

« Reply #5 on: January 20, 2013, 06:15:25 PM »

Since both Japan and Australia have license classes restricted to 10W output on HF,
I wouldn't be surprised if there is some feature that will allow it.

Following up on your comment about the filter board, I reviewed the manuals that I
have on hand for the TS-430 and TS-450.  Both appear to have a switch or jumper
that changes the maximum output level.  It is included on different boards between
the two versions, so I can't give you reliable information for the TS-440, but it would
seem that it is included somewhere.

If that doesn't work, then adding a resistor in series with the top of the PWR pot (which
can be done internally at one of the connectors, probably in a way that can easily be
removed later) would allow easier adjustment:  I've used both of the rigs at 5 watts
without problems, but generally using CW where I could use the CARRIER control to
adjust the output level.  (And it's been many years since my TS-430 was stolen, so
I can't remember it reliably.)

Posts: 906

« Reply #6 on: January 25, 2013, 03:51:46 AM »

Why bother? I doubt that anyone would prosecute you for running 15 watts  instead of 10 watts. How are you measuring the power? If you using the average ham meter or even a  bird, you would be lucky if you got 15% accuracy. It could even be worst if you reading power while connected to the antenna. Another point  is that the efficiency of the  amplifier in the radio will vary from band to band. You will probably find that the power is lower on 10 meters.

The best way to be sure is use  what ever wattmeter you have and feed it into a dummy load. Adjust your power to the lowest level that you can using carrier power. Connect an oscilloscope across the dummy load. Make  the adjustments on the scope so that you can read the level  easily. Then switch over to SSB and just use your mic gain   so that when you drive the radio its below the carrier point. If you oscilloscope has enough bandwidth you can measure power more accurately than the average  ham wattmeter. Its the best peak power reading device you can have in the ham shack.  If the radio inspector came and visited you  he would probably leave you alone because he would see that you have an oscilloscope and you are doing your best  to measure peak power accurately. It would also indicate that you technically minded and know what you doing. Besides the oscilloscope is a handy thing for modulation  monitoring to prevent over driving.

Another problem with TS430S is that if you  bought it secondhand and dont know the history of the radio, you will probably find some idiot has tried to adjust the radio for more power output. The TS430S
is one of these radios that can splatter pretty badly if some incompetent  fool has had his screwdriver inside  trying to get more power out of the radio. If you unsure it might be wise to get a real technician to tune the radio for you.
A proper technician could easily adjust the drive level internally to give you 10 watts exactly, its pretty easy to do.

I work a lot of you F calls on 15 meters. Most of these stations are not running 10 watts I know that Smiley I think there are many that are running as  much 1kw or more. Because we have all been hams for decades we just know what is possible.  Besides the largest number  of hams  in the world that ran 10 watts were the Japanese hams. I have worked them for more than 30 years, we all know what is possible and what is impossible! Nobody else in the world can  run a G5RV or even a triband beam with 10 watts and be 5/9plus. So if these stations are doing it and getting away with it they not  going to be concerned about your miserable 5 watts extra.

I must saying imposing a power level as low as 10 watts is ridiculous. They should have made the legal limit 25 watts. This would have been 6db down from 100 watts.  25 watts is enough power for beginners to work the world on any
band if you run a decent antenna. If you cant do it on 25  watts you need better antennas.

 I also notice that  a lot  your new F calls run this bassy ESSB audio, which is the worst TX audio you can run for working DX. I reallystruggle hearing this rubbish crap bassy audio from weak stations.  If you reduce the bandwidth of your SSB bandwidth you can increase the signal to noise ratio by as much as 10db. I find it astonishing that they let hams who  are supposed to be learning the fundamentals of radio, and yet they allow these hams
to run wide  ESSB which is hardly appropriate for a low power SSB station.

I have the kenwood ts440s/at and I heard it goes down to 10 how could I do that and if it only goes down to 15 if I turn down the mic gain to get to 10 from 15
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