[Amps] Henry 2K-4 Failure

[mark bitterlich]

Nichrome wire would have to dissipate 75 watts of heat unless it was mounted on stand-offs with air flow. Otherwise that heat will go directly to the socket thus quickening their demise as they lose spring tension on the filiment sockets. Which happens anyway, but this will speed it right along. Or you might just swap a tube to figure out which is bad and you're done ...with 50/50 odds of getting it right the first time. Sometimes the most obvious method is the best one. And not all pairs of 3-500's have filaments in series.MarkWa3jpyWho has changed many many 3-500's
-------- Original message --------From: Adrian <vk4tux at gmail.com> Date: 3/20/20  10:50  (GMT-05:00) To: Jim Thomson <jim.thom at telus.net>, amps at contesting.com Subject: Re: [Amps] Henry 2K-4 Failure Yes I earlier divided 10 volts by 15 amps to get 0.666 series resistance divided by 2  (tubes)1.5 ft 16 gauge nichrome coiled is a inexpensive option.On 21/3/20 12:16 am, Jim Thomson wrote:> ## would require a  .333  ohm  at  75+  watt  resistor.>> Jim   VE7RF>>> -----Original Message----- From: Adrian> Sent: Thursday, March 19, 2020 3:17 PM> To: Jim Thomson ; amps at contesting.com> Subject: Re: [Amps] Henry 2K-4 Failure>> Thanks Jim, you can't beat words from those experienced.>> I guess a cathode test plug could be made to substitute one tube> plugging into>> the socket .A dead tube could have its base made up for this, with> resistor added to>> cathode connections equalling the hot value.>> Then interchange tubes on the remaining socket to compare.>>>> vk4tux>>>>> On 20/3/20 3:32 am, Jim Thomson wrote:>>> Grid to cathode short & ?stayed failed? means you just need an>>> ohmmeter. No need to swap tubes, etc.>>>>>> Gerald, VE1DT>>>>> ##   Nope.  The  grid  to cathode  short  only  happens  with tube  >> fil lit.....  not  when  cold.>> When  cold,  both  a HI  pot  tester....  and  also  a megger wont  >> work either.>>>> Jim    VE7RF>> _______________________________________________>> Amps mailing list>> Amps at contesting.com>> http://lists.contesting.com/mailman/listinfo/amps>>>>_______________________________________________Amps mailing listAmps at contesting.comhttp://lists.contesting.com/mailman/listinfo/amps