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

[Roger]

Carl wrote:
> Roger, I use the usual cap bypassing at the input plus a HD LC filter 
> (keeps RF out of the house wiring)built into each 240V metal outlet 
> box. Then MOV's right inside the main panel at each breaker going into 
> the shack plus ones for the refrigerator. Others right at the well 
> pump, and oil burner. Only 3-4  failures (non flamable MOV's but they 
> sure stink) in the 21 years Ive been here, knock on wood.
OK, this part I've pretty well covered.  (Wish  had a few of those 
really big ones we used at work, but they're a bit beyond my budget).  
OTOH I do have a whole box full of those for 120 and 240 VAC although I 
don't remember the joule rating.
>
> On the secondary, a single .0047/.005 across each diode string and 
> another to ground at the output. Rated at 3X the PS DC.
>
> A reverse connected 1N5408 across each filter cap.
>
> Finally the usual HV surge (glitch) resistor and a real HV fuse, 
> sometimes 2 of them.
>

> Jim, VE7DX, probably has some suggestions when you get into serious 
> voltages and zillions of joules in the capacitor bank. I havent 
> reached that level yet.
>
I don't think my budget is going to take me there<:-)) 

 I have one, what I consider a really good amp with the likely hood of 
buying  (if the budget permits later this summer) or building, or 
modifying one to comfortably run the legal limit on six, and another for 
low bands to use here in the den. I do like that YC-156, or 179, but 
they are so darn big physically. I do like the 3CX3000 which would fit a 
reasonable size desk top and it's instant on. Of course the 4CX5000 is 
also instant on compared to the YC156 or YC179), BUT that honker takes 
over 560 watts just to light the fire while the 4CX3000A takes 373 
watts.  Actually I have a 156 sitting on the shelf as a decoration. It's 
*supposed* to be good, but looks rough. Who knows until it's tested? . 
If I decided to go that route I'd probably purchase a tested one from 
WA8WZG and stick with around 3KV on the plate for a reasonable size 
power supply and have an amp that'd easily run the legal limit with a 
tube that'd outlast my grand kids. (Now IF it was just 2" shorter 
<sigh>) OTOH the typical 3CX and 4CX 1500's, or 3CPX 800's, or Chinese 
FU728F's will get the job done with room to spare in a rather compact 
desk top unit.  Too bad those tetrodes don't go to two meters.<:-))

73

Roger (K8RI)
>
> KM1H
>
>
>> Carl,
>>
>> What do you use for spike suppression and where do you put it?  
>> Across each cap? Across the transformer primary?
>>
>> Carl wrote:
>>> I get a bit carried away with spike suppression and fault limiting. 
>>> Had an amp blow on me about 40 years ago and said never again!
>>>
>>> Carl
>>> KM1H
>>>
>>>
>>>
>>>
>>>> Thanks, that's what I usually hear when I look into electrolytics.
>>>>
>>>> And I think you hit the nail on the head with spike 
>>>> suppression...that may
>>>> be the reason that operating with a safety margin is recommended. 
>>>> Most HV PS
>>>> designs I have come across (in my admittedly limited experience) do 
>>>> not have
>>>> any kind of protection.
>>>>
>>>> 73, Carl WS7L
>>>>
>>>>
>>>>> -----Original Message-----
>>>>> From: Carl [mailto:km1h at jeremy.mv.com]
>>>>>
>>>>> IMO the only rule is the heat rise.
>>>>> ...
>>>>> This also assumes spike suppression is used.
>>>>>
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>
>