¿ªÔÆÌåÓý

ctrl + shift + ? for shortcuts
© 2025 Groups.io
Date
Re: 3-500Z socket.... max current ratings
wrote: them XX% design, filters, manufacturers
By pentalab <jim.thomson@...> · #1022 ·
Re: Inrush filament current protection
<rbonner@...> wrote: RIGHT NOW that had me thinking the same thing. ### huh ? AS long as you have a relay/contactor/ ckt breaker that opens OFF BOTH sides of the 240v line... anything beyond that is a
By pentalab <jim.thomson@...> · #1021 ·
Re: ARRL - Political - was: Filament Voltage regulator
My next door neighbor growing up wanted to be a priest. In the late 60s he spent 3 years going to school then all of a sudden dropped out. I asked him why he changed his mind a couple years later. He
By FRANCIS CARCIA <carcia@...> · #1020 ·
Re: Inrush filament current protection
For the life of me, I can't figure out why you would need one for each line lead? If the voltage drops, the current rises making the same output power from the transformer. The same amount of power
By craxd <craxd@...> · #1019 ·
Re: Can a ..power factor correction cap be used on the input of a Plate Xfmr ??
Jim, I've seen these used, but they were used in smaller DC supplies. I have several books on the subject and will look it up. That value though seems way to much at 35 uF for this. Placed across the
By craxd <craxd@...> · #1018 ·
Re: ARRL - Political - Hiram Percy maxim
Hirams Percys father, Hiram Stevens Maxim was the daddy of the Maxim machine gun that helped cause all the carnage in WWI. Though the Browning machine gun eventually won out during US government
By craxd <craxd@...> · #1017 ·
Re: Inrush filament current protection
Amplifiers that run on two voltages need two step-start resistors, but those that run on one V need only one R L Measures, AG6K, 805.386.3734 r@..., rlm@..., www.somis.org
By R L Measures · #1016 ·
Re: Inrush filament current protection
Garry, That is a great question. I have a couple projects going together RIGHT NOW that had me thinking the same thing. It depends on if you cheat or not. OK what does that mean? 220V wiring is 2 wire
By Robert B. Bonner <rbonner@...> · #1015 ·
Inrush filament current protection
When running an amp on 240 volts, is it necessary to put a resistor in both sides of the 240 volt line for inrush current protection or would a single resistor of adequate size in one leg do the job?
By Garry Drummond <g.drummond@...> · #1014 ·
Re: 3-500Z socket.... max current ratings
All of Jim's points are valid and a good amp designer will take them into account. I would just caution anyone on adding an arbitrary XX% of airflow "just in case". If you are serious about your amp
By Bill Turner <dezrat@...> · #1012 ·
Can a ..power factor correction cap be used on the input of a Plate Xfmr ??
Gents My buddy tried this... said it worked. He gave me a 32 uf cap to try it myself. It gets installed directly in parallel with the pri of the plate xfmr. [this is for a C input HV supply]. I didn't
By pentalab <jim.thomson@...> · #1011 ·
Re: 3-500Z socket.... Johnson vs Eimac
By R L Measures · #1013 ·
Re: 3-500Z socket.... max current ratings
wrote: #### Well.. Eimac specs ceramic metal tubes for a seal temp of 250 deg C [482 deg F] On a triode... this is where the lower portion of the anode just touches the ceramic "stem". The top part of
By pentalab <jim.thomson@...> · #1009 ·
Re: ARRL - Political - Hiram Percy maxim
Not according to history, Jim.
By R L Measures · #1010 ·
Re: 3-500Z socket.... max current ratings
... provided that if the tube blows out of the socket, the operator can catch it on the fly. R L Measures, AG6K, 805.386.3734 r@..., rlm@..., www.somis.org
By R L Measures · #1008 ·
Re: ARRL - Political - Hiram Percy maxim
--- In ham_amplifiers@..., RICH SEZ... opposite page (p.9) there's a picture of the inventor of the firearms silencer, Hiram P. Maxim, wearing a set of headphones - but strangely he is
By pentalab <jim.thomson@...> · #1007 ·
Re: ARRL - Political - was: Filament Voltage regulator
By R L Measures · #1006 ·
Re: 3-500Z socket.... Johnson vs Eimac
past. however the ### Drake uses the same Johnson sub mounted sockets on the L4B. [came out in 1969].. on aluminium cylinder standoffs. The 3-500Z spec is for only .08" h2o... which is easy to
By pentalab <jim.thomson@...> · #1005 ·
Re: 3-500Z socket.... max current ratings
The only absolutely guaranteed measure of correct airflow is to measure the temperature of the tube seals as specified by the tube manufacturer, under full load for long enough for the tube to reach
By Bill Turner <dezrat@...> · #1004 ·
Re: 3-500Z socket.... max current ratings
I have never seen an amplifier with a cooling system like a SB-220's.
By R L Measures · #1003 ·