"Albert & Btittany Spear" wrote in message
...
I have never heard of a neutralization procedure like this you mention.

I have always done a neutralization WITHOUT excitation.

Is this procedure you describe from an owners manual for a commercial
rig?

I happened to have a 1976 Handbook handy. Page 163 details
the grid current method of neutralization in a screen -grid amplifier.

"... As a final adjustment, ... the neutralization adjustment should be
continued to the point where minimum plate current, maximum grid
current, and max. screen current occur simultaneously."

73

Pete

Behold, Uncle Peter scribed on tube chassis:

snip

From a safety standpoint, the manufacturer would rather have the B+
removed for adjustments.

Also pull g2, lest you cook your screens.

--
Gregg "t3h g33k"
http://geek.scorpiorising.ca
*Ratings are for transistors, tubes have guidelines*

Wrap the fuse with Reynolds aluminum foil. Don't use plastic-wrap, that
won't work. Insert the fuse, then rotate all knobs for max out.

Jump the screen drop resistor and you'll get about 190 Bird watts out with
good swing.

I'd install a Christmas Tree in place of the 6X4 rectifier for more output.

Wrap the final tubes with a layer of Teflon plumber's tape. In case the
glass shatters during tune-up, the shards won't get into the bandswitch.

Replace all caps in the speech amp with Vitamin Q's for better sonic
clarity.

Good Luck


"Gary" wrote in message
...
I bought a TS-830 from a ham friend that buys estates etc. He couldn't
get more than 30 watts out of the '830. I tried it and by putting the
drive control at a low level then dipping the plates and adjusting the
load control and finally increasing the drive control I was able to
get 100 watts out. Then the rig went dead. I checked the fuse on the
back and it was blown. It was a 3 amp fuse but right underneath the
fuse holder in white lettering it said 6A I'm wondering if the '830
should have a 6 amp fuse instead of the 3 amp fuse that was in there ?

Also I noticed that even when the plates were dipped correctly that
the plate current meter at 100 W out was almost pinned to the max,
maybe it needs neutralization ?

Thanks in advance.

Gary

You will blow the fuse if you spend too much time with the key down.
I used to run RTTY, reducing the power to 60 watts or so. You would
be safe tuning up in TUNE position, but need to go CW for the full
power touchup. There should be no reason to lean on it for more than
5 seconds at a time.

Nutralization is easy. Adjust bias for 55 ma. no drive, then tune
up the radio normally on 28 MHz. and switch the screen grids off on
the back panel and adjust neut cap for minimum output on a receiver.
Use an insulated screwdriver or you will burn out the plate choke.
When you are through, plate dip and maximum RF output should be very
close (but not usually exactly coincidental) and maximum RF output
should occur at 225-250 ma. IP. Always tune rig for maximum RF
output for cleanest signal and reduce drive for your needs.

ac6tk
"Dick Suhar PE CMfgE" wrote in
message ...
Fuse value depends upon what line voltage the unit is set up for.
The TS830S
can be either the 110VAC or 220VAC....you know.. higher voltage
lower
amperage.

Neutralization need is not indicative of a power supply problem..
look at
the rectifier unit assembly and check for a problem there.. ripple
, hum,
wrong primary winding wiring set up.

73
Dick
_____________________________________________
"Gary" wrote in message
...
I bought a TS-830 from a ham friend that buys estates etc. He
couldn't
get more than 30 watts out of the '830. I tried it and by putting
the
drive control at a low level then dipping the plates and
adjusting the
load control and finally increasing the drive control I was able
to
get 100 watts out. Then the rig went dead. I checked the fuse on
the
back and it was blown. It was a 3 amp fuse but right underneath
the
fuse holder in white lettering it said 6A I'm wondering if the
'830
should have a 6 amp fuse instead of the 3 amp fuse that was in
there ?

Also I noticed that even when the plates were dipped correctly
that
the plate current meter at 100 W out was almost pinned to the
max,
maybe it needs neutralization ?

Thanks in advance.

Gary

It is 6amps, just like the stamp said.

Dan/W4NTI

"Gary" wrote in message
...
I bought a TS-830 from a ham friend that buys estates etc. He couldn't
get more than 30 watts out of the '830. I tried it and by putting the
drive control at a low level then dipping the plates and adjusting the
load control and finally increasing the drive control I was able to
get 100 watts out. Then the rig went dead. I checked the fuse on the
back and it was blown. It was a 3 amp fuse but right underneath the
fuse holder in white lettering it said 6A I'm wondering if the '830
should have a 6 amp fuse instead of the 3 amp fuse that was in there ?

Also I noticed that even when the plates were dipped correctly that
the plate current meter at 100 W out was almost pinned to the max,
maybe it needs neutralization ?

Thanks in advance.

Gary

Also I noticed that even when the plates were dipped correctly that
the plate current meter at 100 W out was almost pinned to the max,
maybe it needs neutralization ?

Thanks in advance.

Gary


I'd also suspect you almost melted down the 6146s with that sort of
plate current. They probably turned cherry red, and arced over,
blowing the fuses. Read the manual.

Pete

As Pete said "it is in some of the handbooks". It is also in some
manufacturers manuals.
It is much easier to do than disconnecting the plate and screen
voltages in most cases. Often disconnecting the screen voltage is a
real chore.
Also all the shielding is left in place and the procedure / check can
be done quickly on any radio.

Some radios can not be perfectly neutralized so you may not be able to
find a position where max output and minimum plate current occur but
you can usually get close.

sometimes using a little less than full drive makes things more
sensitive and it is easier to make the adjustments.

I have seen radios that would not neutralize properly and I had to
change the values of the neutralizing capacitor to either a larger or
smaller than the original.
This can also happen if you change the type of 6146 tubes used. The
6146B verses a plain 6146 for example will require a different value
of neutralization capacitance. If the original capacitor will not tune
far enough then it will have to be changed to do the job.

When watching for maximum grid current and minimum plate current for
proper neutralization there is an exception.. The Collins kwm2, 32s1
etc. use negative feedback in the final and driver stages. When
properly set up and neutralized the grid current should dip slightly
when the plate current dips on these radios. This is due to the plate
voltage increasing at plate current dip (a normal thing in any radio)
and part of it is fed back to the grid out of phase to create the
negative feed back. That out of phase voltage causes the grid current
to decrease.

73
Gary K4FMX


On Tue, 19 Jul 2005 20:15:22 GMT, "Albert & Btittany Spear"
wrote:

I have never heard of a neutralization procedure like this you mention.

I have always done a neutralization WITHOUT excitation.

Is this procedure you describe from an owners manual for a commercial rig?


"Gary Schafer" wrote in message
.. .
A check for proper neutralization can be done with full drive and the
final tuned properly. Watch the power output and the plate current as
you change the final plate tuning capacitor. Minimum plate current
should occur at exactly the point of maximum output. If it does not
the neutralization is off.

If you can observe grid current, the grid current should peak at
exactly plate current dip also.

You can rotate the neutralization cap slightly and try the above
again. It will get worse with one direction of rotation of the plate
tune with a particular direction of rotation of the neutralization
cap. A little diddling and you will be able to determine which way to
go.

73
Gary K4FMX

On Sun, 17 Jul 2005 15:43:05 GMT, Edward Knobloch
wrote:

Hi,

I would think that you would use a 3 amp fuse if wired for 220V,
6A for 110V (I don't have a Kenwood manual to check this,
but a 6 amp fuse sounds right at 110V).

First check your resting plate current before tuning up.
With PTT set to transmit, and no drive/no audio,
the finals should draw about 40mA plate current.
If not, adjust the bias control for this reading.

The proper way to dip a pi net final is to start with the loading
capacitor fully meshed. Apply some drive and quickly dip the final
plate current using the plate tune control only.

Then apply full drive* (see note) and read the plate current
(it should be much less than the rated 250 mA).
Assuming it is less than the desired 250mA,
increase the loading control slightly
(say, enough to result in a 20 mA increase in plate current
with full drive)and then quickly redip
using the plate tuning control.
(+Always+ redip with the tuning control last,
or you will be operating with your final out of resonance).
Note that you are always dipping with full drive applied.

Note that you can dip the final using the plate tune control
while less than full drive is applied (easier on the tubes),
but you then must increase the drive to full drive to see
if you have reached 250mA plate current at dip
with full drive, which is your goal.

Continue this procedure until either the rf power output
no longer increases when you increase the load control
with drive,
or you have reached 250mA plate current at dip with full drive,
whichever comes first. Do not operate with more than
250mA plate current at dip, full drive, or you will overheat
your finals.

*Note: By "full drive", I mean enough drive for the plate current
to stop increasing very much with increasing drive (saturated),
not that the drive control is fully clockwise.

If you don't get around 100W rf out at 250mA dipped plate current,
one possibility is that the final tubes are not well balanced.
With the bias set for 40mA with both finals installed,
if you remove one, the resting current should be 20mA.
If the tubes aren't well balanced, one tube may be hogging
all the current, and the rig will be unable to deliver more than
about 50 or 60 Watts. Note: remove one of the tubes
completely for this check, do not just remove the plate connector
of the unused tube, or it may be damaged by excessive screen current
(the screen tries to act like the plate). Caution: high voltage
at plate caps of the 6146's - keep one hand in your pocket
when you poke around near the final cage. Use a shorting stick
before touching the plate cap.

To check neutralization, you transmit with no drive,
PTT on, no audio, (i.e., same set-up as 40 mA bias check),
and with the loading capacitor fully meshed, you rock
the plate tuning capacitor throughout its full range.
The plate current meter should remain at 40mA.
Any sudden, drastic increase as you vary the plate tune
capacitor with no drive in this manner indicates
a neutralization problem. Note: this can be a destructive
test, as the onset of a parasitic oscillation can be sudden,
with very high plate current. Be ready to turn off
the final quickly. A dummy load is best for this test,
rather than an antenna.

73,
Ed Knobloch


Gary wrote:
I bought a TS-830 from a ham friend that buys estates etc. He couldn't
get more than 30 watts out of the '830. I tried it and by putting the
drive control at a low level then dipping the plates and adjusting the
load control and finally increasing the drive control I was able to
get 100 watts out. Then the rig went dead. I checked the fuse on the
back and it was blown. It was a 3 amp fuse but right underneath the
fuse holder in white lettering it said 6A I'm wondering if the '830
should have a 6 amp fuse instead of the 3 amp fuse that was in there ?

Also I noticed that even when the plates were dipped correctly that
the plate current meter at 100 W out was almost pinned to the max,
maybe it needs neutralization ?

Thanks in advance.

Gary

Uncle Peter wrote:
Also I noticed that even when the plates were dipped correctly that

the plate current meter at 100 W out was almost pinned to the max,
maybe it needs neutralization ?

Thanks in advance.

Gary


I'd also suspect you almost melted down the 6146s with that sort of
plate current. They probably turned cherry red, and arced over,
blowing the fuses. Read the manual.

Pete

Dip the grids, and peak the plates, then watch the finals evaporate...

-Chuck