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Identifying some rare tubes...
I've been offered this job lot from a SK sale... I recognise 3CX15k, 4CX5k, Gu81m, ITL9-1, BR1106, Vac-Vars (10-200, 25kV) any idea's for the rest? There are some kanji characters on the big glass
By Tim Fern · #40271 ·
Re: Kudos to Digi Key and Hammond Mfg.
Like Steve said, Digi Key is the only way to order them. The original in my amp was a Magnelab. They are poorly built and according to Glenn, all of the Magnelab transformers have failed. Alpha was
By NI5L <ni5l@...> · #40270 ·
Re: Ameritron Plate Chokes
Atr 50Hz 1.2A will be permitted when winding a transformer with that wire. At free air 14A will be maximum. 73 Peter, DJ7WW -----Original-Nachricht----- Betreff: Re: [ham-amplifiers] Ameritron Plate
By Peter Voelpel · #40269 ·
Re: Ameritron Plate Chokes
Oopsie... I didn't notice earlier that you mentioned the 8K's choke is wound on teflon... Steve, K0XP
By Steve · #40268 ·
Re: Ameritron Plate Chokes
Yup; PTFE's a pretty good thermal insulator at low temperatures (i.e.: below its melting or burning point), especially compared to ceramic. Moreover, the ceramic can take a couple thousand degrees
By Steve · #40267 ·
Re: PA tube testing, Interesting findings.
Kinda hard to fit a 3CX3000-anything into a 7-inch-high desktop cabinet, even without anything connected to the top or bottom? 8-)
By Steve · #40266 ·
Re: Ameritron Plate Chokes
While on a roll, I tested both my Ameritron plate chokes.... by hooking em up to my small 0-36 vdc @ 3 amp CCS lab supply. They will take 1.5 amps CCS, and run at room ambient temp for hrs.? ?They
By Jim VE7RF · #40265 ·
Re: Inductive EHT filtering
Don't nobody be intending to call and talk to Tim on the phone over the weekend; he'll have his ears plugged with wads of paper in anticipation of those bangs? 8-D -- See my QRZ.com page at
By Steve · #40264 ·
Re: Inductive EHT filtering
"?They will work for B+ applications, but have to be-derated for voltage.".... that's the question, right there. If it's rated 8kV, will it cope with 6,500V?? Because if it doesn't , 800J is going
By Tim Fern · #40263 ·
Re: PA tube testing, Interesting findings.
If you are using more than one tube, you are using the wrong tube! 73, Mike Mysliwiec KF8OD
By Mike · #40262 ·
Re: PA tube testing, Interesting findings.
How do you match them up...even if they are good ?? ? ?2 tubes are bad enough....and 3 of em is a pita. I ran into this same problem eons ago on hb amps.? 2 x really good tubes...when tested one
By Jim VE7RF · #40261 ·
Re: Kudos to Digi Key and Hammond Mfg.
I tried ordering my replacment 2K4A XFMR from Dahl/Hammond, and they told me I had to order it through DigiKey because DK was now their distributor; so I did. Initially, there was some confusion; the
By Steve · #40260 ·
Re: Kudos to Digi Key and Hammond Mfg.
Why did u have to go through digikey..and not directly with hammond / dahl ? NO hv sag at all, that's superb. IMO, whatever the B+ is? with amp keyed, and sucking normal idle current is the real no
By Jim VE7RF · #40259 ·
Re: Inductive EHT filtering
Some oil caps were meant for energy discharge, ( like laser discharge)? and have higher internal ESR.? ?They will work for B+ applications, but have to be-derated for voltage.? ?Typ oil caps used
By Jim VE7RF · #40258 ·
Re: Inductive EHT filtering
By Tim Fern · #40257 ·
Re: Inductive EHT filtering
Hi Jim, I've spent more time modelling it now but I'm still not happy with the overshoot with sudden load changes Plus, I've come by an "energy storage" capacitor rated 38uF at 8kV. (It's 22" tall, 6"
By Tim Fern · #40256 ·
Re: Inductive EHT filtering
You are correct.? A MOV? from each winding...to chassis? is a wasted effort.? ?I didn't think of what happens if the spark gap arced, when the choke is part of a choke input (resonant or not).?
By Jim VE7RF · #40255 ·
Re: Inductive EHT filtering
Well then... since what we're REALLY concerned about is keeping the voltage difference between the choke winding and iron core low enough that it never arcs over and causes damage, what about a
By Steve · #40254 ·
Re: Inductive EHT filtering
I was thinking about a RVS connected diode across the choke..... but Hammond/dahl read me the riot act, said...'don't even think about it'.? ?They are correct of course, since the normal Voltage
By Jim VE7RF · #40253 ·
Re: Ameritron Plate Chokes
Here.? ? ?https://www.ctrengineeringinc.com/contacting-us-please-read/
By Jim VE7RF · #40252 ·