[Amps] HV lytic max V ratings..some notes

[Carl]

>
>
>> ## The ameritrons will do 1.5 kw out, so will qro/command/
>> palstar/Emtron.  they all have 3.5 kva xfmr's in em.
>
> ** Youre starting to sound like someone we know, making up specs on the 
> fly
> (-:
> Grab a real Dahl catalog and run the math. Example is the Commander 2500
> Heavy Duty replacement is 900V @ 2A ICAS. The AL-1200, etc is 2570V @ 
> 800ma
> ICAS
>
> ###  How do u get 1.5 kw CCS, RF output [2.5 kw input, 60% eff]  from a 
> 1200 va CCS
> xfmr  [Comander 2500]     or a 1370 va CCS  [ AL-1200]  xmfr ??



** By writing the spec sheet and not dead key for long. There is a big 
difference in a ham version of CCS in a 70 # table top amp and the same CCS 
and power in a 700# military/commercial 24/7 equivalent.
Its all marketing BS in the ham arena.




>
> ##  My 46 lb dahl is rated for 2750 vac @ 1A  CCS = 2.75 kva.  All the 
> dahl
> 46 lb's are aprx the same CCS kva.   The next size up is the 68 lb.  Then 
> it's
> 2750 @  1.5 A  CCS = 4.125 kva.
>
> ##  you are probably correct.  The xfmr's in these table top amps are 
> grossly
> undersized.....and way over rated.    A  46 lb dahl would be the bare min 
> to use
> in any 1.5 kw out  RTTY rated amp.


** Yep


>
>>
>>> I can understand 330-560uF
>>> which  still may place a strenuous starting load on stock amps.
>>
>>> ## install step start....pretty simple.
>>
>>
>> ** More junk to buy, find room for, and eventually blow unless its
>> overbuilt. The Harbach stuff is marginal in a SB-220. Amp Supply uses 
>> step
>> start in most models.
>
>
>>
>> ## The fix for..'not enough room for step start' is to install it
>> outboard.
>>>
>> ## It's either that.. or fry on/off switch's.. and also  cw/ssb  switchs.
>> Without
>> the step start, the peak current is an easy 160-190A through the on/off
>> switch..
>> albeit for only a split second.
>>
>
>
> ** I could also buy a Mini, place it on a custom tube frame and running
> gear, stretch the nose and run a blown hemi.
> Thats about as ridiculous as adding a bunch of outboard crap to a good
> working amp.
>
> ## suit yourself.  I don't  like the idea of frying, and replacing  cw/ssb
> and also  main of/off switch's all the time.  I don't like hearing the..
> thhhhummmp, when you 1st turn em on either.  A ramped up triac
> would be another option.. and take up less space.   In the meantime,
> a small outboard step start box solves all those problems... and also
> allows to step start, when toggling between  cw + ssb modes.  It also
> step starts the fils as well. Throw it on the floor, behind the desk.  I 
> built
> a  few of em  for fellow's  here in town.  They operate smoothly.  Put as 
> much
> C  in the Hv supply as you want.  A  10 ohm, 100w  Arcol /dale metal 
> finned
> resistor and 2 x 30A  P+B  PRD  series  relays  works great.


** Different strokes for different folks. I cant see bothering with 
something that works, looks good on the SA and doesnt get OTA complaints.
I dont scream into the mike and run a lot of processing either so the real 
world rigs IMD is probably much better than a mostly useless 2 tone test at 
full power.


>
>> ## Then get a Class A  ricebox.  When toggling between Class A.. and AB
>> the difference is just un-real..esp when listening off freq.. with a 2nd
>> RX..aprx 4' away.  S-9 crud  drops to zero.
>
>
> ** I wouldnt waste my money on a new ricebox. Its simple enough to rebias
> the TS-940 and add more cooling. Or just use the TS-830. Im less concerned
> about HF IMD where Im rarely on SSB except in an already noisy DX pileup. 
> On
> VHF and up I take it pretty serious.
>
> ## IF you re-bias the TS-940's final  PA.... you also have to re-bias the
> driver as well.... or ur wasting your time.


** In the 940 the PA module is one removable assembly that includes the 
drivers and final and easy to work on. In fact the last stage drivers are 
more critical than the finals and have to be a certain Beta color code.



>>
>> **  Some tubes cant take all that stored energy from your overkill caps
>> without something better than a glitch resistor. We dont all run YC-156,
>> 3CX3000A7, 3CX6000A7, 4CX10000A, and bigger like your crowd do.
>>
>> ## better imd, far better bang for the buck, rebuildable in most cases.
>> You
>> can buy any of the above tubes for a lot less, than what it cost to
>> re-tube
>> a 87-A.
>
>
> ** How does that help the appliance operator that already has an amp?
>
> ##  It doesn't.   It MIGHT provide him with an incentive to hb his next
> amp.  A  $225  YC-156 is a huge bang for the buck.. and no socket 
> required.
> No suppressor required either. Just add a surplus 4160/4800 vac  pole pig, 
> and
> 2 x pi nets [ input + output], 2 x meter's....2 x T/R relays and your 
> done.
> 35w of drive= 1.5 kw.   It just goes up from there.


** And pretty soon he takes up a full room with heat and noise and the 
family walks out (-;
Not everyone is as tolerant as my old lady!

** My basement is somewhat sound proofed so the folks upstairs dont hear 
anything unless a speaker is blasting and I use headphones 99% of the time. 
On AM Ive no tolerance for locked mike windbag monolouges and just QSY and 
find or start another QSO.

Carl
KM1H


>
> later... Jim   VE7RF
>
>
>
> Carl
> KM1H
>
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