Yes in a Class C amplifier one typically will adjust the plate circuit
tuning for a dip in plate current. Then one should adjust coupling for
rated plate current or rated output. Then adjust the plate tuning to the
"for right side of resonance", typically increasing PA current about 5%
which will produce maximum efficiency. All of this applies to only Class C
amplifier stages.
In a linear amplifier, adjust plate circuit tuning for maximum output which
should also be at the same point as the peak in grid current. Then work
your way up the power scale by increasing drive while adjusting loading to
keep grid current and plate current at or below maximum ratings. Once the
rated grid and plate current values are attained, controlled by drive, the
last step is a very minor adjustment of plate tuning for maximum output.
Remember should one use light loading with a linear amplifier, splatter
abounds!
73
Bob, K4TAX
----- Original Message -----
From: "Rick - DJ0IP / NJ0IP" <Rick@DJ0IP.de>
To: "'Discussion of Ten-Tec Equipment'" <tentec@contesting.com>
Sent: Saturday, March 01, 2014 4:14 PM
Subject: Re: [TenTec] In praise of older technology
"Dip" was pre-watt meter days.
No need to dip anymore.
Just tune for maximum smoke!
Precisely, running full drive power, you first tune the PLATE for max
smoke,
then repeat the sequence of slowly advancing the LOAD and peaking the
PLATE
for max smoke.
If you reach the point where increasing the LOAD and peaking the plate
brings no more increase in max smoke, but just an increase in Ig, then
you've gone too far. Back it off.
The idea is to find the exact point where max smoke is reached with min
LOAD
that can achieve it - and of course all of this is always subject to the
Ig
not exceeding max specs.
Piece of cake.
The only thing I do different in practice is, I first tune for max smoke
with about 30w of drive, just to get everything in resonance, then I
proceed
as described above.
Dip? 40 years ago, maybe!
73 - Rick, DJ0IP
(Nr. Frankfurt am Main)
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Bob
McGraw
- K4TAX
Sent: Saturday, March 01, 2014 10:00 PM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] In praise of older technology
The only thing I ever "dip" is a little chew.
73
Bob, K4TAX
----- Original Message -----
From: "Brian Carling" <bcarling@cfl.rr.com>
To: "Ed Purvis" <wa4njy@yahoo.com>; "Discussion of Ten-Tec Equipment"
<tentec@contesting.com>
Sent: Saturday, March 01, 2014 2:18 PM
Subject: Re: [TenTec] In praise of older technology
Ed you must be talking about those XE stations tuning up on SSB on the
low
end of 40m. They groan "hoooooo-la" while they dip the plate control !
SOP
Best regards - Bry Carling
On Feb 22, 2014, at 8:29 PM, Ed Purvis <wa4njy@yahoo.com> wrote:
There are some on hi-fi sideband that I am not sure they are talking or
their stomach is making noise.
________________________________
From: Steve Berg <wa9jml@frontier.com>
To: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Sent: Saturday, February 22, 2014 8:12 PM
Subject: Re: [TenTec] In praise of older technology
As part of my collection, I have Drake 2B receiver and a Gonset GSB100
phasing exciter. One night I wound up in a round table with a bunch of
HiFi SSB aficionados 0n 40 meters. These guys were running advanced
equalizers and high-end microphones. Then had the latest Oriental
Transceivers. They even had audio spectrum analyzers to check out each
others signals. So, I asked for an evaluation, and they were quite
complimentary. So, they asked what I was running, and I told them a
1957 vintage phasing exciter with a D104 mic. They were amazed! Sure,
it drifts, and it is hard to get it right on frequency by zerobeating
the receiver BFO with the carrier on the exciter. But it is a lot of
fun to use.
Steve WA9JML
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|