Re: [Drakelist] Leaving tube radio on
Bud - Not really, compared to the heat and _mechanical_ shock each time it's turned on For cathode type tubes, (most small receiving tubes and some transmitting tubes,) what 'wears out' in a tube is the electron emitting cathode coating. Weak tubes are often a result of the cathode coating being damaged (by on / off cycling?) rather than a 'worn out' filament. Another cause of tube 'failure' is shorts between elements, some developing from small chunks of cathode material breaking off, due to temp cycling? I still think it's better to leave tube gear ON if you intend to use it 'in reasonable period of time'. If you're not going to use it for a day or two, leave it off, but if you're 'likely' to use it again the same day, leave it ON. Assuming of course that it has adequate cooling, and is properly fused. Just my opinion, yours is welcome! 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line and TR-4/C Service Supplement CDs www.k4oah.com sebdesnCC wrote: Sorry if this is dumb, but doesn't a tube that is on and the filament on degrade the tube just by being hot and glowing??? Bud W0HG ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] On...or off?
Tom - Good compromise! :-) This was common in LOTS of tube gear before the 'greenies' attacked and demanded we unplug our electric toothbrushes!! They would have stroked over the 'Damp Chaser' Hallicrafter's and others used in receivers. For the youngsters, a 'Damp Chaser' was an accessory sold at the time. It was a power resistor that you bolted to the chassis of a receiver that was connected across the line at all times. The all occurred before electricity went to 25 cents a kWH!! Somehow the free market works these things out MUCH better than government, or other, edict 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line and TR-4/C Service Supplement CDs www.k4oah.com TC Dailey wrote: Back in the day... I borrowed an idea from the color-TV instant on feature... soldered a reverse-biased diode across the ON/OFF switch, so that only the negative-going pulses entered the power xfmr - it would light the filaments half-brilliance, but no B+ was generated. the radios would be instant on with very little drift after initial power-up. NEVER had a problem. Tom - WØEAJ ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] On...or off?
Tom - I just re-read your message... Just HOW do you connect a 'reverse-biased diode' to AC???:-) 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line and TR-4/C Service Supplement CDs www.k4oah.com TC Dailey wrote: Back in the day... I borrowed an idea from the color-TV instant on feature... soldered a reverse-biased diode across the ON/OFF switch, so that only the negative-going pulses entered the power xfmr - it would light the filaments half-brilliance, but no B+ was generated. the radios would be instant on with very little drift after initial power-up. NEVER had a problem. Tom - WØEAJ ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] On...or off?
Don - This definitely helps mitigate turn-on surge currents. It's critical to get the 'right size', and to mount it away from other components, as they DO get hot in operation. 'OH NO, 'wasted' power!' They also reduce the voltage applied to all components by a small amount, which doesn't hurt with today's considerably higher line voltages. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line and TR-4/C Service Supplement CDs www.k4oah.com Don Cunningham wrote: I am trying a thermistor from Mouser on my 516F2 power supply for the KWM2A at the suggestion of a friend. I don't notice the thump on the transformer anymore, so it may just be enough of a delay to help protect switches, transformers, etc. Sure initially looks like cheap insurance!! I'll post something again after I've really tested this longer term. I will try one on an AC4 also. 73, Don, WB5HAK ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] On...or off?
I use to keep the tube rigs warm and happy until I got the electric bill They are turned off now. I'm not talking about one or two rigs either, there are dozens in the shack, and they hit the electric up to the point they had to go dark. mike Mike Bryce, WB8VGE the heathkit shop SunLight energy systems J e e p o|||o On Sep 10, 2011, at 9:54 AM, Garey Barrell wrote: Don - This definitely helps mitigate turn-on surge currents. It's critical to get the 'right size', and to mount it away from other components, as they DO get hot in operation. 'OH NO, 'wasted' power!' They also reduce the voltage applied to all components by a small amount, which doesn't hurt with today's considerably higher line voltages. 73, Garey - K4OAH Glen Allen, VA ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] On...or off?
On Sat, 10 Sep 2011 09:50:28 -0400, Garey Barrell wrote: the 'greenies' attacked and demanded we unplug our electric toothbrushes!! And yet, most of our modern electronics draws a small amount of standby power to accomodate remote controls, soft power buttons, etc. I guess that's OK The HW-101 that I had back in the late 70s had an ugly homebrew power supply with a switch on it to kill the B+. I used to let it run with the filamants lit all the time. It helped keep my room warm in the winter. 73 -Jim -- Ham Radio NU0C Lincoln, Nebraska, U.S.S.A. TR7/RV7/R7A/L7, TR6/RV6, T4XC/R4C/L4B, NCL2000, SB104A, R390A, GT550A/RV550A, HyGain 3750, IBM PS/2 - all vintage, all the time! Give a man a URL, and he will learn for an hour; teach him to Google, and he will learn for a lifetime. HyGain 3750 User's Group - http://groups.yahoo.com/group/HyGain_3750/ http://incolor.inetnebr.com/jshorney http://www.nebraskaghosts.org ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] On...or off?
So do you just put one of these devices in series with the hot line of the AC mains? Guy, WA6OQQ On 9/9/2011 9:06 PM, Jim Shorney wrote: On Fri, 9 Sep 2011 22:44:35 -0500, Don Cunningham wrote: I am trying a thermistor from Mouser on my 516F2 power supply for the KWM2A at the suggestion of a friend. I don't notice the thump on the transformer anymore, so it may just be enough of a delay to help protect switches, transformers, etc. I've salvaged NTC thermistors out of dead PC power supplies, they usually seem appropriatly sized for linear loads up to a few hundred watts. Have one in my PS-7 and one in an AC-4. It tames the thumps nicely, and anyone who has a PS-7 knows that it has a monster thump. See here: http://zerobeat.net/drakelist/smf/index.php/topic,252.0.html 73, -Jim -- Ham Radio NU0C Lincoln, Nebraska, U.S.S.A. TR7/RV7/R7A/L7, TR6/RV6, T4XC/R4C/L4B, NCL2000, SB104A, R390A, GT550A/RV550A, HyGain 3750, IBM PS/2 - all vintage, all the time! Give a man a URL, and he will learn for an hour; teach him to Google, and he will learn for a lifetime. HyGain 3750 User's Group - http://groups.yahoo.com/group/HyGain_3750/ http://incolor.inetnebr.com/jshorney http://www.nebraskaghosts.org ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist -- ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] On...or off?
On Sat, 10 Sep 2011 07:47:02 -0700, Guy Giacopuzzi wrote: So do you just put one of these devices in series with the hot line of the AC mains? Yep. See the article by DL7MAJ that I posted the link to. They do get warm in normal operation, so you want to allow them room to breathe. 73 -Jim -- Ham Radio NU0C Lincoln, Nebraska, U.S.S.A. TR7/RV7/R7A/L7, TR6/RV6, T4XC/R4C/L4B, NCL2000, SB104A, R390A, GT550A/RV550A, HyGain 3750, IBM PS/2 - all vintage, all the time! Give a man a URL, and he will learn for an hour; teach him to Google, and he will learn for a lifetime. HyGain 3750 User's Group - http://groups.yahoo.com/group/HyGain_3750/ http://incolor.inetnebr.com/jshorney http://www.nebraskaghosts.org ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Leaving tube radio on
No,Garey, I will defer to your infinitely better knowledge,in most everything radiowise,,,thanks for the info!! Bud -Original Message- From: drakelist-boun...@zerobeat.net [mailto:drakelist-boun...@zerobeat.net] On Behalf Of Garey Barrell Sent: Saturday, September 10, 2011 7:44 AM To: 'drakelist' Subject: Re: [Drakelist] Leaving tube radio on Bud - Not really, compared to the heat and _mechanical_ shock each time it's turned on For cathode type tubes, (most small receiving tubes and some transmitting tubes,) what 'wears out' in a tube is the electron emitting cathode coating. Weak tubes are often a result of the cathode coating being damaged (by on / off cycling?) rather than a 'worn out' filament. Another cause of tube 'failure' is shorts between elements, some developing from small chunks of cathode material breaking off, due to temp cycling? I still think it's better to leave tube gear ON if you intend to use it 'in reasonable period of time'. If you're not going to use it for a day or two, leave it off, but if you're 'likely' to use it again the same day, leave it ON. Assuming of course that it has adequate cooling, and is properly fused. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] R4A AC
What is the optimum AC current for the R4A? Are the 100.00 variacs on Ebay good enough for bringing up Drake tube equipment? ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R4A AC
A 60W light bulb in series with the AC line works just as well or better, and is a lot easier, (and cheaper!) It also prevents you from turning the Variac up to 130+ VAC, which most will do all too easily. An R-4A should draw a little less than 0.5A after warm up. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line and TR-4/C Service Supplement CDs www.k4oah.com Neil M Califano wrote: What is the optimum AC current for the R4A? Are the100.00 variacs on Ebay good enough for bringing up Drake tube equipment? ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] R4 Cabinet Questions
I am in the processing of saving an older R4 from the dumpster so some one can enjoy it. The copper is pretty darn good but it is missing the top and bottom of the black cabinet. Can I use any Drake top/bottom on this R4 or am I limited to the genuine R4 Top/Bottom combo. Hamfest season is gearing up for me and want to be able to know what I am shopping for. It could take a while to fine the genuine article and if I can use something from a R4A or B or C it might make the search a bit easier. Steve NU0P ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
