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[Amps] Re SB220 HV; Transformer Wanted thread stolen

To: "amps@contesting.com" <amps@contesting.com>
Subject: [Amps] Re SB220 HV; Transformer Wanted thread stolen
From: "Roger (K8RI)" <k8ri@rogerhalstead.com>
Date: Wed, 6 Nov 2019 01:09:30 -0500
List-post: <mailto:amps@contesting.com>
Many computer accessories and USB drives use 3 to 5A power supplies. I have a 5A Netgear router PS plugged into a remote, 10 TB USB hard drive. It's a switcher, but absolutely silent.  There's no such thing as a standard connector so you might need to modify, or replace the one on the PS. Then, again you might get lucky.

73, Roger (K8RI)

On 11/4/2019 1:52 AM, Roger (K8RI) wrote:
My opinion:
In the  "old days" we were expected to tune into a dummy load and match the antenna with a tuner using low power as we are today

The big Henry amps were usually run well beyond the legal limit, so tuning beyond a KW was no different than running 3 to 5 KW SSB, or CW. The difference in "those days" was the FCC enforced the rules so you generally needed to be much more careful when running your California KW. Of course with today's VNAs it's quite easy to get the SWR right down to 1:1 so tuning into a DL and then switching to the antenna requires no peaking. If everything is matched and the signal is clean, "GENERALLY" no one bothers you unless the signal is obnoxiously strong and creates problems.for others. I don't believe the FCC has the manpower now days to go after anyone except the really bad apples.  If you read the FCC actions, they typically are for hams who are causing malicious interference.  In those cases power may be mentioned..

The knowledge level on the bands is abysmal. It reminds me of when working as a GA for my masters. I was teaching the intro to Computer Science to 5 classes with a max of 40 per class. I had a total of 195 students.  This was for non CS students. Mostly business majors. I had around 5 ot 10 who weren't going to make it.  I had another 5 or 10 who were at, or above my level. IOW, for them it was a "blow off" class, but in general the knowledgeable level in there was abysmal too.

I spend a lot of time on FB, helping new hams.  With the new testing, they have no technical knowledge.  Virtually none! Typically the old timers are merciless and when they do try to help, the new hams knowing nothing get angry because they think they are being talked down to.

The gap in technical knowledge is tremendous so explaining to these new hams using the technical language is a lost cause and having taught to this level, I can understand why they feel snowed under and talked down to.and why there is so much animosity.

73, Roger (K8RI)

On 10/31/2019 9:30 AM, Mark Bitterlich wrote:
Hi Gary, thanks for your reply.

Yes, I was around when regulations were based on input power (1968) and have heard your explanation before but I tend to question it simply because the Henry 3K and 8K series of amps also came stock with the CW/SSB selection and
either of those two could easily exceed 1000 watts DC input in the CW
position.  FSK and AM modes were also advised to use CW and not SSB modes possibly with plate dissipation limits in mind as well as legal issues of
input power.

But based on the typical pair of 3-500's say in the 3K original designs, in CW mode idling current was 90-120 ma, and in the higher plate voltage SSB
position  170-220 ma.

My logic was simply:

Bias controls the class of amplifier.
A change in bias means the class of amplification must have also changed. Switching from CW to SSB causes an indicated bias change from 120 ma to 220
ma.
The impact of a bias change of  120 to 220 ma would lead me to believe that the class of amplifier shifted slightly in a more linear direction with also
the result of slightly lower efficiency.

Right or wrong or maybe just trivial ...  if wrong could you please explain
your logic?

Mark
Wa3jpy

-----Original Message-----
From: Gary Schafer [mailto:garyschafer@largeriver.net]
Sent: Wednesday, October 30, 2019 10:13 PM
To: 'mark bitterlich'; 'Joe Subich, W4TV'; 'Joe'; amps@contesting.com
Subject: RE: [Amps] SB-220 HV Transformer Wanted

No. The amp runs AB2 meaning it draws grid current.

The reason for the CW/SSB switch was to allow tune up at 1 KW DC input on
CW.
This was the regulation at the time the amp was designed. You were not
allowed to ever exceed 1 KW DC input, even during tune up.
Switching to SSB after CW tune up allowed higher PEP input by maintaining the same plate load impedance (where the amp was tuned)for the higher power.
In other words the voltage to current ratio remained the same when the
higher voltage was selected.

73
Gary  K4FMX

-----Original Message-----
From: Amps [mailto:amps-bounces@contesting.com] On Behalf Of mark
bitterlich
Sent: Wednesday, October 30, 2019 4:23 PM
To: Joe Subich, W4TV; Joe; amps@contesting.com
Subject: Re: [Amps] SB-220 HV Transformer Wanted

Ok, this brings up a technical question that pertains to the topic
amazingly enough. When you shift from single sideband to CW on this amp
are you or are you not moving the class of operation from AB1 towards
AB2 and thus  improving efficiency?MarkWA3JPY


-------- Original message --------From: "Joe Subich, W4TV"
<lists@subich.com> Date: 10/30/19  16:36  (GMT-05:00) To: Joe
<nss@mwt.net>, amps@contesting.com Subject: Re: [Amps] SB-220 HV
Transformer Wanted On 2019-10-30 3:12 PM, Joe wrote: > Why need
them?Some people prefer to keep their equipment "stock" or at
leastfunctionally stock.  The SB-200 was never designed for 1500Woutput
on CW - it was designed to operate at 1 KW DC input (ca.700 W CW or 1500
W PEP SSB output).Pushing the SB-220 to 1500 W CW output (or worse,
running RTTYon the high taps) is a quick way to fry something.  Even
thetoroidal transformer you recommend is only rated for 800 W!73,    ...
Joe, W4TVOn 2019-10-30 3:12 PM, Joe wrote:> Why need them?> > Run it at
the HV side and use less drive and less currents all around.> > The
CW/SSB switch I converted into a stand-by switch.> > Joe WB9SBD> Sig>
The Original Rolling Ball Clock> Idle Tyme> Idle-Tyme.com>
http://www.idle-tyme.com> On 10/30/2019 1:38 PM, Joe Subich, W4TV
wrote:>>>> >> https://www.antekinc.com/as-8t800-800va-transformer/>>>>
Unfortunately, this transformer lacks the primary taps for CW/SSB>>
operation of the OEM device.>>>> 73,>>>>    ... Joe, W4TV>>>>>> On 2019-
10-30 10:23 AM, Joe wrote:>>>>>> On 10/30/2019 8:56 AM, Joe wrote:>>>>
Morning Dick,>>>> If you are not afraid of making a few electrical and
mechanical >>>> modifications, I would go with this transformer.>>>>
https://www.antekinc.com/as-8t800-800va-transformer/>>>>>>>> I'm glad I
did! 1/4 the cost of most drop in replacements. yet MUCH >>>> better
performance!>>>> Joe WB9SBD>>>>>>
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--
Roger (K8RI)


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