[Amps] Decline of homebrewing?

[Charles Farr]

Doesn't anybody remember the "2 man rule"? I have individuals that 
belong to my lodge that work alone, even though I constantly remind them 
to get someone to be with them. Another valuable lesson from the 
military experience.

Chuck, W6AJW


On 01/07/2017 10:13 PM, Jim Thomson wrote:
> Date: Sat, 07 Jan 2017 21:30:23 +0000
> From: Manfred Mornhinweg <manfred at ludens.cl>
> To: amps at contesting.com
> Subject: Re: [Amps] Decline of homebrewing?
> Steve, and all,
>
>> I was nearly killed at age 15.
> ##  heres my sob story.  I was building a heath  GR-64  SW rx  between xmas + new year  1969.  Age 14
> My mum was  cooking dinner, and I was in the den, just off of the kitchen.  I had just finished building the
> kit after several days..and a had 3-4  components left over.  Thought to myself that heath was not too smart to
> be supplying parts that were not required.    Of course, when plugged in and turned on.... it was dead silent.
> I take off the lid, and flip it upside down.... and this is a tube RX.   I start probing around...with my fingers....with zero test gear,
> then got zapped with 300 vdc  off one of the filter caps..it was unplugged too.  Let out a scream, and went flying across the room.  Mother
> freaked out, and figures Im in way over my head, and has a fit.   Being from the UK, she thinks nobody should touch anything unless
> they have 1st completed the 7 year apprenticeship  in the appropriate field.   My older sisters  boyfriend at the time  was a physics
> lab  instructor at the local university, and had a lot of experience with HB electronics..and also fixing every heath /  dynaco / knight kit in town.
> He fixes it in a few hrs, and all is well.  3-4 components were indeed required.
>
> ##  fast forward   to 1974.     Bought a used HB  2 x  813  amp..with NO  B+ voltage meter.   Great fun driving it with  200 w po  from my used
> drake  TR-3  xcvr.   1100 w out.  Nobody even knew what IMD was back then, and could care less.   I short out the  filter choke on the fully exposed
> B+  supply, for even more B+.
>
> ## wanting more power,  around 1976,  I  buy a used  HB single  3-400Z  rf deck, no cabinet, no B+ meter, and no B+ supply.   I build a hb  5 kv no load  B+
> supply, and also cabinets for both the B+ supply + the RF deck.   Filter caps were a mess of  series and parallel 2-4-6 uf  oil caps....and no bleeder.   Drove the
> 3-400 Z with the TR-3.  No tuned input on the rf deck. 1700 w out of a single 3-400Z.  Tube ran bright orange to sorta yellowish.
> Was working out of  town those days, a week at a time.   B+ supply had been  OFF from sunday eve to the following friday night.   4 inch diam muffin was sorta loose,
> so tightened it with an xcelite   nut driver.   Tube was in the way, so tried to work around it.   Tried tightening the top pair of corner screws, and shaft of nutdriver
> was  touching the glass.    Shoulda yanked the tube but was in a rush,  contest on that weekend.  To get the driver to fit, I slide my fingers down onto the steel nutdriver shaft,
> and try to get the nuts tightened.    Wearing a T shirt with bare arms exposed.   Nut driver shaft touches the plate cap of the 3-400Z..and  also had both forearms resting on the
> aluminum  box.   Top lid was removed.   I get thrown 7 feet across the room, and wake up 5 mins later..dripping in sweat.
>
> ##  lesson learned was oil caps will stay charged for at least 5 days..... esp when  stupid enough to not include a bleeder.
> After that it was B+ meters wired in both the RF decks  and also the external B+ supplies. Bleeders  used, and ditto with shorting sticks etc.
>
> ##  Got zapped a few times while working at the telco....and each time was up 7-10 feet off the ground on a rolling ladder.   AC is bad news.
> B+  will throw you across a room..and both will easily kill you.    Had a buss bar explode in my face while trying to pry a stuck fuse out.   Blew
> a hole in the square shaft of the large screwdriver I was using at the time.   I almost had it out when the shaft touched the partially recessed mounting screw
> for the insulator block assy..in the rack.   I had shorted the input buss side of the bank of fuses.  Now you know why there is at least one guy in every
> telco office nicknamed ..... sparky.
>
> Jim   VE7RF
>
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