05/03/2019 20:55

I have acquired an NMR linear amp made by AMP UK using two 3CPX800A7
tubes. It's bought "as seen and untested" Apart from the RF power
meter smashed and a coupling centre insulator missing on one of the
two 1000pF vac variables all LOOKS well. These tubes are hard to find
and expensive so I want to test them first, as best I can. I have the
usual meters and a decent Hi-Pot tester, what's the safest way to
ensure their functionality before powering it up? I don't have the pin
configuration for them, so if anyone has them, or a link to them I
need that info first :) The amp is designed for 400kHz to 1MHz, so I
am toying with using it on MF at some stage. My Eimac Power Grid Tubes
book doesn't give the pin configuration and surprisingly Googling
hasn't found them either. Thanks.

If the tubes are good I have a bargain, if not I have a good source of
some nice bits.

Sold the Pythons in the 70s. Went through a lot of ammo, but one as clean as I kept those, buying one now
would probably cost more than both of those new.

73, Roger (K8RI)

Another item for your perusal






------------------------------------------------------------------------
*From:* "jim.thom@... [ham_amplifiers]" <ham_amplifiers@...>
*To:* ham_amplifiers@...
*Sent:* Tuesday, January 15, 2019 2:04 PM
*Subject:* Re: [ham_amplifiers] 'Toll free' gets blasted with 6 kv !



"whirly gig atom-smasher thingy".? ? ? ? ?That just cracks me right up.? ?Sounds like a great title for a project...for? 73 magazine. Ever seen those industrial labels, typ on a blue / black back ground, with etched? white letters.
?"whirly gig atom smasher thingy" complete with skull? + crossbones seems fitting.? ? Then an? AC/DC? logo on the back end.

?

Jan 11 7:32 PM

##? does it show the HV cabling between em ?? ?Post em anyways. Those pix are awe inspiring.?

Ok, so when? you local RI shows up one day and asks.. 'what the hell are you up to'?? ? ?Just tell em you are working on a prototype..'atom smasher'.?

Jim? VE7RF

You didn't hear thru the grapevine, I emailed you and sent pics.


Yes, it is true that I got tagged.? Three times.

It was NOT a direct hit, as some of the ass clowns keep trying to make it seem.

I did NOT grab the connector, the wire, nothing of the sort.

I had my arm on top of an amp cabinet that was completely buttoned up and went to brush some cables behind the amp away.? My hand got too close to an abraded wire going into a Millen connector.? It cause three arc flashes.? The first one pulled me in to the connector as it caused a spasm.? The second hit me pretty Fing hard, and I threw my entire body back as I was tagged a third time.

I have a backhand opened up like a razor knife.? The current traveled through the ticker, twice. Once when it blew a hole out of my leg and again when it blew a hole in my fingertip on the opposite hand.



This was not anything being worked on.? The amp was a trade.? Turns out, the last owner got electrocuted, too. Turns out the fucking idiot couldn't install a Millen correctly.



I'm VERY lucky to be alive.

I now have a tightness in my chest during any times of stress that I can only equate as this:? When I was a cigarette smoker and I had a bad chest cold when I would smoke a cig, that feeling in your chest then.? If you've never smoked, you won't get it.

I now have every two week appts with a cardiologist, a dermatologist and a pulmonologist.? These will continue for a year, along with biweekly visits to my primary care physician (which coincide with the off weeks at the specialists).? Have to carry aspirin, etc.

The docs don't //believe// I have any long term damage, but we won't know until it's said and done (about a year passes).


I'm still able to work (I'm an electrician, yes, I keep having to tell the story over and over), so that is a blessing. My right hand is fine, my left the blisters are peeling off and I still have 3 open wounds, same as my leg..



Anyway, hope that kind of sets the record straight.

180uF at 6kv 3 times.? 2.5A CCS xformer on a 60A breaker. My kids called me the 6 Thousand Volt man.



I have since converted to positive locking real hv connectors.? HSV. Google that shit.? Coupled with rg59, you can't go wrong.


73 everyone.? I'll be lurking from time to time.? Guess it wasn't my time to go visit Rich Measures yet!

--Shane
KD6VXI
Toll_Free
On Wednesday, December 19, 2018, jim.thom@... <mailto:jim.thom@...> [ham_amplifiers] <ham_amplifiers@... <mailto:ham_amplifiers@...>> wrote:

I heard through the grape vine that toll free / aka? Shane,? /?
KD6VXI,? just about blew his finger off, on a Millen

HV connector, with 6 kv on it.? ?Don't ever get near one of those
things, when there is B+ on it.


Jim? ?VE7RF

?

First reply:

"A good number of FM broadcast transmitters above 10 KW TPO have external power supplies, as do most of the old big-iron 50 KW tube transmitters....some of which used what were essentially reverse-connected "pole pig" transformers to generate the 15 KV plate voltage. Tube TV transmitters can run even higher...30 KV or more...and they all have external HV power supplies. But NONE of them use any sort of connector in the HV lines."

I had posted that I doubted that such xmitters with eternal B+ supplies existed...

Change of subject: In that "I Take Pictures of Transmitter Sites" that I mentioned, somebody posted a pic of a big whirlygig atom-smasher thingy...? Just on a lark, not knowing the guy (and, certainly, him never having heard of ME) I posted something like "John Lyles, isn't that something like you use at work?"...He's a humble guy, but he replied that yes, it was, but kinda hinted at the fact that it was just a smallish version. That must be very satisfying, when the crowd knows who you are, when you didn't know you HAD a fan club.

73

Randy

KZ4RV

On 1/11/2019 9:38 PM, Randy randy@... [ham_amplifiers] wrote:

?

I just posed the question to "AM/FM/TV Broadcast Engineers" page on FaceBook, and if that doesn't generate any helpful replies, I might go off-topic on the "I Take Pictures of Transmitter Sites" on FB, lots more people there, and nothing they haven't seen or done.

What ever happened to Bob, DD? Used to work on Top Fuel dragsters? Those Vertex ignition magnetos must crank out a shitload of voltage @ X current...I'm not suggesting, necessarily, that somebody should mount jimmied spark plugs in the cabinets at each end of the wire, but those boots on the plug wires, with the deeply recessed electrode might be just the ticket, if the connectors could handle the current, *and* didn't pull off when you tug on them. I'm pretty sure Top Fuel machines vibrate hard enough to simulate the maid dusting behind the cabinet if you had some form of strain relief.

If it wasn't a bad idea, Carl would already be doing it, given his track time...

Randy

KZ4RV

On 1/11/2019 4:32 PM, jim.thom@... [ham_amplifiers] wrote:

?

Jan 4 9:33 AM

<? My hand got too close to an abraded wire going into a Millen connector.??

##? do u mean a strand of the? GTO neon sign wire was hanging out the side ???

##? My problem with millens is the metal on back end of male..is hardly recessed.? ?Drake? used heat shrink over the back end of the male.... but not? right? down to the HV wire....other wise,? u can't rotate the male millen.? ?It also needs? nylon screws on the female.?

##? although some of the HV connectors are rated for? HV, they are really? hv, low energy types.? ?As opposed to? ?HV / high energy types.?

##? The? SHV connectors? u alluded to? are only rated for? 5 kv @? 3A.? shv =? 'safe high voltage'.? ?They are essential? reverse? gendered? bnc's... with real long? barrels.?

##? The MHV is? ?'miniature high voltage'?

##? and in all cases, they tell u NOT to touch em with HV on !?

##? I 'forgot'? to book mark another? hv connector,? it was made for? 213 / 393 coax.? ?I will try and find it...rated for? I think? 25-40 kv? working..and? ? 75-100 kv test.? ?And a lot of current, like? 20A? ?CCS.? ?The male / female each were aprx? 3-? 3.5"? in length, dunno about price.?

##? at least? with shielded? HV wire, like coax, then way less chance of? stuff going wrong? ..with shield? bonded to chassis? at each end.? ?NO exposed B+.? ?Inside the cab, I just use .25"? belden? HV wire, rated for 10 kv ac? working V.? ?( 20 kv test).? 18 gauge stranded wire used.? ?no shield.? Just? silicone rubber, comes in either? red or black.? ?Neon sign wire can be bought in blue.using the same? silicone rubber.? ?u can get neon sign wire, like gto brand, with bigger wire, like? 12/14/16 gauge.?

##? Im just gonna hardwire either? 213? or? 393 between cabs.? Then? strain relief? at both ends...like hte type where the twist lock? reduces? diameter, till it pinchs the cable? tightly.? Then leave some slack, then terminate? with a stakon/ crimped and soldered..onto top of a 1" diam? x? XXX long ceramic stand off.? ? A wrap around plastic clamp.... like u use on ends of a bifilar rod..for more strain relief.... just b4 it gets to top of standoff.? ?maybe a 2nd clamp as well.? ? Then peel back braid a good? 3", cut off braid, with just? say? 1/2"? exposed, then wrap some strap around the exposed braid, solder it... then? run strap to chassis / metal...repeat at both ends of hv cable.? ?

##? Like how often are u gonna? have to remove the cable at one /both ends ???? ?I have hinged? front /rear key lock doors on the cab with xfmr..and quick rls side? panels.? Rear hinged door has a plastic re-enforced? aprx 1.75" diam hole for cables to pass through....like the? pair of? 1-0 cu power cables,? B+? etc, etc.? They all terminate? with strain relief.? ? Then I can still? unlock rear door... and open it......and not affect? strain relief setup.? ? hole is? close to hinge? side of rear door.?

##? Life is a lot easier when the? RF deck is at top of rack...and HV supply at bottom of rack, then all HV wiring is internal.... but in my case, I can't do that.? ?

##? I'd like to know what? fm / am broadcast stations use...IF? HV? has to be routed external? from one cab to an adjacent cab.? ? On 2nd thought,? at work, we had? 5 x cabs, all? 7'? tall? x? 24"? wide? x? 31" deep... and they are all bolted? together.? ? 20 x casters in total. 4 per cab.? NO side walls between? adjacent cabs..and all had locking rear doors.? ?All the cabling was between em internally...or out the bottom, through the false floor we used... tiles lifted up with the? suction tool..exposing? miles of cabling. real floor was? 15" below the false? tiled floor...each tile sat on a? ?steel? square grid, with vert supports to real concrete floor below it.?

That cavity down below also had compressed cold air inside it... which cooled each cab in the room.?

Most cabs these days? have either a? 9.5"? square hole in the bottom, dead center? of bigger, like? ?11 x 15 ".? ??

? ?Just don't lose keys to any keyed door,? I keep em in the door lock at all times.? ?My side panels? are quick rls types,? with 1/4 turn cam locks, just a screw driver required in 4 x places.? ? They can be replaced with keyed locks if required.?

Millen and? 7 kv really don't belong in the same sentence.? ?One day my 240 line drifted up to 247.2 vac .? ?B+ went from it's usual aprx? 6750 vdc? up to almost 7000.? ?Then chassis female arced on the inside? from center connection..to one of the 2 x machine screws that hold down the? female chassis millen.? ?That was with? a? 50 uf? @ 9 kv oil cap inside the box.? Sounded like a bomb? going off.? ?The 'fix'? at the time was to re-locate the? 2 red and 2 black millens to side of cab..and onto round sheets of red HV mircarta and? also nylon screws.?

The millen is still a stupid connector..since no way to use braided coax? with it.? ? The aldens are no better.? ?

Jim? ?VE7RF?

?

I just posed the question to "AM/FM/TV Broadcast Engineers" page on FaceBook, and if that doesn't generate any helpful replies, I might go off-topic on the "I Take Pictures of Transmitter Sites" on FB, lots more people there, and nothing they haven't seen or done.

What ever happened to Bob, DD? Used to work on Top Fuel dragsters? Those Vertex ignition magnetos must crank out a shitload of voltage @ X current...I'm not suggesting, necessarily, that somebody should mount jimmied spark plugs in the cabinets at each end of the wire, but those boots on the plug wires, with the deeply recessed electrode might be just the ticket, if the connectors could handle the current, *and* didn't pull off when you tug on them. I'm pretty sure Top Fuel machines vibrate hard enough to simulate the maid dusting behind the cabinet if you had some form of strain relief.

If it wasn't a bad idea, Carl would already be doing it, given his track time...

Randy

KZ4RV

On 1/11/2019 4:32 PM, jim.thom@... [ham_amplifiers] wrote:

?

Jan 4 9:33 AM

<? My hand got too close to an abraded wire going into a Millen connector.??

##? do u mean a strand of the? GTO neon sign wire was hanging out the side ???

##? My problem with millens is the metal on back end of male..is hardly recessed.? ?Drake? used heat shrink over the back end of the male.... but not? right? down to the HV wire....other wise,? u can't rotate the male millen.? ?It also needs? nylon screws on the female.?

##? although some of the HV connectors are rated for? HV, they are really? hv, low energy types.? ?As opposed to? ?HV / high energy types.?

##? The? SHV connectors? u alluded to? are only rated for? 5 kv @? 3A.? shv =? 'safe high voltage'.? ?They are essential? reverse? gendered? bnc's... with real long? barrels.?

##? The MHV is? ?'miniature high voltage'?

##? and in all cases, they tell u NOT to touch em with HV on !?

##? I 'forgot'? to book mark another? hv connector,? it was made for? 213 / 393 coax.? ?I will try and find it...rated for? I think? 25-40 kv? working..and? ? 75-100 kv test.? ?And a lot of current, like? 20A? ?CCS.? ?The male / female each were aprx? 3-? 3.5"? in length, dunno about price.?

##? at least? with shielded? HV wire, like coax, then way less chance of? stuff going wrong? ..with shield? bonded to chassis? at each end.? ?NO exposed B+.? ?Inside the cab, I just use .25"? belden? HV wire, rated for 10 kv ac? working V.? ?( 20 kv test).? 18 gauge stranded wire used.? ?no shield.? Just? silicone rubber, comes in either? red or black.? ?Neon sign wire can be bought in blue.using the same? silicone rubber.? ?u can get neon sign wire, like gto brand, with bigger wire, like? 12/14/16 gauge.?

##? Im just gonna hardwire either? 213? or? 393 between cabs.? Then? strain relief? at both ends...like hte type where the twist lock? reduces? diameter, till it pinchs the cable? tightly.? Then leave some slack, then terminate? with a stakon/ crimped and soldered..onto top of a 1" diam? x? XXX long ceramic stand off.? ? A wrap around plastic clamp.... like u use on ends of a bifilar rod..for more strain relief.... just b4 it gets to top of standoff.? ?maybe a 2nd clamp as well.? ? Then peel back braid a good? 3", cut off braid, with just? say? 1/2"? exposed, then wrap some strap around the exposed braid, solder it... then? run strap to chassis / metal...repeat at both ends of hv cable.? ?

##? Like how often are u gonna? have to remove the cable at one /both ends ???? ?I have hinged? front /rear key lock doors on the cab with xfmr..and quick rls side? panels.? Rear hinged door has a plastic re-enforced? aprx 1.75" diam hole for cables to pass through....like the? pair of? 1-0 cu power cables,? B+? etc, etc.? They all terminate? with strain relief.? ? Then I can still? unlock rear door... and open it......and not affect? strain relief setup.? ? hole is? close to hinge? side of rear door.?

##? Life is a lot easier when the? RF deck is at top of rack...and HV supply at bottom of rack, then all HV wiring is internal.... but in my case, I can't do that.? ?

##? I'd like to know what? fm / am broadcast stations use...IF? HV? has to be routed external? from one cab to an adjacent cab.? ? On 2nd thought,? at work, we had? 5 x cabs, all? 7'? tall? x? 24"? wide? x? 31" deep... and they are all bolted? together.? ? 20 x casters in total. 4 per cab.? NO side walls between? adjacent cabs..and all had locking rear doors.? ?All the cabling was between em internally...or out the bottom, through the false floor we used... tiles lifted up with the? suction tool..exposing? miles of cabling. real floor was? 15" below the false? tiled floor...each tile sat on a? ?steel? square grid, with vert supports to real concrete floor below it.?

That cavity down below also had compressed cold air inside it... which cooled each cab in the room.?

Most cabs these days? have either a? 9.5"? square hole in the bottom, dead center? of bigger, like? ?11 x 15 ".? ??

? ?Just don't lose keys to any keyed door,? I keep em in the door lock at all times.? ?My side panels? are quick rls types,? with 1/4 turn cam locks, just a screw driver required in 4 x places.? ? They can be replaced with keyed locks if required.?

Millen and? 7 kv really don't belong in the same sentence.? ?One day my 240 line drifted up to 247.2 vac .? ?B+ went from it's usual aprx? 6750 vdc? up to almost 7000.? ?Then chassis female arced on the inside? from center connection..to one of the 2 x machine screws that hold down the? female chassis millen.? ?That was with? a? 50 uf? @ 9 kv oil cap inside the box.? Sounded like a bomb? going off.? ?The 'fix'? at the time was to re-locate the? 2 red and 2 black millens to side of cab..and onto round sheets of red HV mircarta and? also nylon screws.?

The millen is still a stupid connector..since no way to use braided coax? with it.? ? The aldens are no better.? ?

Jim? ?VE7RF?

?

Jan 4 9:33 AM

<? My hand got too close to an abraded wire going into a Millen connector.??

##? do u mean a strand of the? GTO neon sign wire was hanging out the side ???

##? My problem with millens is the metal on back end of male..is hardly recessed.? ?Drake? used heat shrink over the back end of the male.... but not? right? down to the HV wire....other wise,? u can't rotate the male millen.? ?It also needs? nylon screws on the female.?

##? although some of the HV connectors are rated for? HV, they are really? hv, low energy types.? ?As opposed to? ?HV / high energy types.?

##? The? SHV connectors? u alluded to? are only rated for? 5 kv @? 3A.? shv =? 'safe high voltage'.? ?They are essential? reverse? gendered? bnc's... with real long? barrels.?

##? The MHV is? ?'miniature high voltage'?

##? and in all cases, they tell u NOT to touch em with HV on !?

##? I 'forgot'? to book mark another? hv connector,? it was made for? 213 / 393 coax.? ?I will try and find it...rated for? I think? 25-40 kv? working..and? ? 75-100 kv test.? ?And a lot of current, like? 20A? ?CCS.? ?The male / female each were aprx? 3-? 3.5"? in length, dunno about price.?

##? at least? with shielded? HV wire, like coax, then way less chance of? stuff going wrong? ..with shield? bonded to chassis? at each end.? ?NO exposed B+.? ?Inside the cab, I just use .25"? belden? HV wire, rated for 10 kv ac? working V.? ?( 20 kv test).? 18 gauge stranded wire used.? ?no shield.? Just? silicone rubber, comes in either? red or black.? ?Neon sign wire can be bought in blue.using the same? silicone rubber.? ?u can get neon sign wire, like gto brand, with bigger wire, like? 12/14/16 gauge.?

##? Im just gonna hardwire either? 213? or? 393 between cabs.? Then? strain relief? at both ends...like hte type where the twist lock? reduces? diameter, till it pinchs the cable? tightly.? Then leave some slack, then terminate? with a stakon/ crimped and soldered..onto top of a 1" diam? x? XXX long ceramic stand off.? ? A wrap around plastic clamp.... like u use on ends of a bifilar rod..for more strain relief.... just b4 it gets to top of standoff.? ?maybe a 2nd clamp as well.? ? Then peel back braid a good? 3", cut off braid, with just? say? 1/2"? exposed, then wrap some strap around the exposed braid, solder it... then? run strap to chassis / metal...repeat at both ends of hv cable.? ?

##? Like how often are u gonna? have to remove the cable at one /both ends ???? ?I have hinged? front /rear key lock doors on the cab with xfmr..and quick rls side? panels.? Rear hinged door has a plastic re-enforced? aprx 1.75" diam hole for cables to pass through....like the? pair of? 1-0 cu power cables,? B+? etc, etc.? They all terminate? with strain relief.? ? Then I can still? unlock rear door... and open it......and not affect? strain relief setup.? ? hole is? close to hinge? side of rear door.?

##? Life is a lot easier when the? RF deck is at top of rack...and HV supply at bottom of rack, then all HV wiring is internal.... but in my case, I can't do that.? ?

##? I'd like to know what? fm / am broadcast stations use...IF? HV? has to be routed external? from one cab to an adjacent cab.? ? On 2nd thought,? at work, we had? 5 x cabs, all? 7'? tall? x? 24"? wide? x? 31" deep... and they are all bolted? together.? ? 20 x casters in total. 4 per cab.? NO side walls between? adjacent cabs..and all had locking rear doors.? ?All the cabling was between em internally...or out the bottom, through the false floor we used... tiles lifted up with the? suction tool..exposing? miles of cabling. real floor was? 15" below the false? tiled floor...each tile sat on a? ?steel? square grid, with vert supports to real concrete floor below it.?

That cavity down below also had compressed cold air inside it... which cooled each cab in the room.?

Most cabs these days? have either a? 9.5"? square hole in the bottom, dead center? of bigger, like? ?11 x 15 ".? ??

? ?Just don't lose keys to any keyed door,? I keep em in the door lock at all times.? ?My side panels? are quick rls types,? with 1/4 turn cam locks, just a screw driver required in 4 x places.? ? They can be replaced with keyed locks if required.?

Millen and? 7 kv really don't belong in the same sentence.? ?One day my 240 line drifted up to 247.2 vac .? ?B+ went from it's usual aprx? 6750 vdc? up to almost 7000.? ?Then chassis female arced on the inside? from center connection..to one of the 2 x machine screws that hold down the? female chassis millen.? ?That was with? a? 50 uf? @ 9 kv oil cap inside the box.? Sounded like a bomb? going off.? ?The 'fix'? at the time was to re-locate the? 2 red and 2 black millens to side of cab..and onto round sheets of red HV mircarta and? also nylon screws.?

The millen is still a stupid connector..since no way to use braided coax? with it.? ? The aldens are no better.? ?

Jim? ?VE7RF?