[Kenwood] ts 520

[mark kenward]

This procedure works fine if you have a resonant antenna to switch over to. 
If not, you'll have to do the whole thing again anyway. It takes seconds. I 
do it all the time.


If your antenna is not 50 ohms, you'll be way off. You will have to 
re-adjust(per Maxwell)

The tank circuit will act like an antenna tuner. Since the optimum load 
impedance for 6146 tubes in parallel is about 2000 ohms, the tank curcuit 
acts like an antenna tuner at all times.  (how many guys have 2000 ohm 
antennas?)

Please read Walt Maxwell's "Reflections II" , section 13.2, pages 13.1 to 
13.3.

" ...so whatever the load on the tank circuit might be, with even a 4:1 swr, 
the tuning and loading control range may allow you to obtain a dip in plate 
current at the same value as with a 50 ohm dummy load.. If so, the tubes are 
seeing their desired load impedance and are operating at the same 
temperature as with the 50 ohm dummy load; no overheating will result from 
the swr on the feed line!"

When tuning up, If the dip is broad, retune the load capacitor to insure a 
sharp dip.

"If normal plate current(and dip) cannot be obtained with ANY setting of the 
loading capacitor, Z2 is outside the matching range of the tank network, 
......(and a tuner must be used)  (Reflections II section 7.5, page 7-13)

Basically Maxwell indicates in this chapter that although your wattmeter may 
be off, the rig will be happy.

Also read chapter 7, section 7.5 concerning matching with a tank circuit.

So I say again.

IF IF  IF  you get a normal dip, and the antenna loads, Have fun.

Best 73,
Mark
K8VF




----- Original Message ----- 
From: "Gary Smith" <wa1tjb at yahoo.com>
To: <kenwood at mailman.qth.net>
Sent: Tuesday, April 19, 2005 4:19 PM
Subject: RE: [Kenwood] ts 520


>I agree with tuning into a dummy load, not only for
> the reason Eric cites, but because it is the right
> thing to do in preventing emissions that disturb the
> bands.  Tune into a dummy load and then go on the air.
> You can get a dummy load for $50 from Ameritron, so
> it's not like they are expensive.
>
> 73 de Gary
> WA1TJB
>
>
> --- Eric Lowell <elowell at maine.rr.com> wrote:
>> Gents,
>>
>> You'd be best off to tune the thing into a dummy
>> load, then switch it over
>> to the antenna. Peak the power out with the drive ,
>> dip the plate current
>> and off you go, THEN put the antenna on. Continuous
>> tuning into an antenna
>> could mean that the dip has his hands on the knobs.
>>
>> Regards, Eric W1EL
>>
>>
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