Gawdamighty, George - that 6BQ5 photo (#5) looks just like Gort melting his way out of the plastic encasement!
Have a safe trip, looking forward to your further adventures in tubal-pyrotechnics! 😎
~ Sam
Have a safe trip, looking forward to your further adventures in tubal-pyrotechnics! 😎
~ Sam
There are no 6BQ5 pictures here. The tube in photo #5 is a 6V6GT.
The last two pictures are of a 6BQ6 sweep tube that died during screen drive experiments. The cause of death was obviously an arc from plate to screen grid, because those elements are severely melted in the same location. Yesterday I thought it was a 6BQ6GT that I killed during the AES tube sale trash. I still believe that's when I killed it, because that's when I got two big boxes full of them for an average of 67 cents each, but closer examination reveals that it was a 6BQ6GA. Note the two holes in the plate.
The first picture shows a 6BQ6GT (rear--no holes) and a 6BQ6GA (front--three holes). These tubes both have the same ratings, but obviously the one in the front can take more abuse. The little guy became known as the leaning tower of power since it couldn't stand up straight, and it and its twin cranked out 125 watts before being killed by a tube arc.
The next picture shows a pair of crusty looking 6BQ6GA's that were "NIB" from AES. Obviously not new, neither did they work very well. So I stuck them in an SSE board which was wired for fixed bias, and proceeded to see just how much power a single small sweep tube could make in UL mode.
The third picture shows what a 6BQ6GA can do when cranked just short of melting. My notes said 20 watts at 3% distortion, but I neglected to write down the plate voltage or current. There are no holes in these plates, so these were not the autopsied tube.
A bit of exploration on my portable hard drive revealed pictures of some 6CB5's being tested in SE UL. Unfortunately, no notes.
The fourth picture shows a Sylvania 6CB5 (left) and an RCA in the hot seat on the right.
The fifth picture shows the RCA at the edge of glow.
rfengineer2013....That is also my occupation, for the last 40 years I have worked at Motorola doing various types of RF design work on two way radios and cell phones.
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My bad - I either mis-read your original post or fat-fingered the keys. Thanks for the breakdown on the photos - absolutely fascinating.
It's also what I do - 35 years working various aspects of RF/Analog design in Aerospace Comm, Medical Telemetry, and lately Commercial Aircraft entertainment system design. Wire-pulling, it's something in the blood.
BTW (OT) - I finished up an SSE last month and have really enjoyed listening to the music. Did a point-to-point hookup, everything went quite well. I was simply amazed at how nice the sound was (is) on my old floor speakers from the very first time I turned it on, compared to what I've been listening to for so many years.
Thanks for the good work you do!
~ Sam
It's also what I do - 35 years working various aspects of RF/Analog design in Aerospace Comm, Medical Telemetry, and lately Commercial Aircraft entertainment system design. Wire-pulling, it's something in the blood.
BTW (OT) - I finished up an SSE last month and have really enjoyed listening to the music. Did a point-to-point hookup, everything went quite well. I was simply amazed at how nice the sound was (is) on my old floor speakers from the very first time I turned it on, compared to what I've been listening to for so many years.
Thanks for the good work you do!
~ Sam
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I've been toying with the PCB design again, if 400V B+ and 40 to 50mA, 16 to 20watts plate dissipation. I removed the diodes and first cap for the B+ so that would have to separate and coupled with the inductor to the PCB. I added a 6CG3 damper for slow start, I've done this for yrs now and like the concept. It has a bypassed 50V for the heater CT and 160V for the G2 gate and nixie tube if used.
My first tube combination will be 6JT6 outputs with 6JT8 drivers. The 6JT6's look like the 6JT8's on steroids.
My first tube combination will be 6JT6 outputs with 6JT8 drivers. The 6JT6's look like the 6JT8's on steroids.
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