Re: [drakelist] AC-4R upgrades

2007-01-16 Thread w1id
An open 220k bleeder resistor makes sense. I guess you could check that by disconnecting it and checking the resistance. Makes me wonder what would cause it to fail. Assuming 250 volts it would need to dissipate 0.28 watt. If it's a 1/2 watt carbon composition resistor, it might have increased

Re: [drakelist] AC-4R upgrades

2007-01-16 Thread Ken Winterling
Ken Winterling [EMAIL PROTECTED] made an utterance to the drakelist gang -- Tom, There is a 220K bleeder/load resistor, R8, across the medium B+, 250V, supply to ground. If it is open the medium B+ will be pulled up toward the

Re: [drakelist] AC-4R upgrades

2007-01-16 Thread Ken Winterling
Ken Winterling [EMAIL PROTECTED] made an utterance to the drakelist gang -- According to Tom this supply also had an open 10K HV bleeder/load resistor. Whatever caused it to fail may have caused the 220K resistor to fail. I'm

Re: [drakelist] AC-4R upgrades

2007-01-14 Thread Tom Taylor
Subject: Re: [drakelist] AC-4R upgrades Donnie Garrett [EMAIL PROTECTED] made an utterance to the drakelist gang -- Tom: I have one of the early AC3 supplies that used a HV choke. Garey K4OAH and I had a lot of discussions about

Re: [drakelist] AC-4R upgrades

2006-12-20 Thread Tom Taylor
in daily use. You wisely chose to use it on the test bench instead. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Donnie Garrett Sent: Tuesday, December 12, 2006 5:27 AM To: Tom Taylor Cc: drakelist@www.zerobeat.net Subject: Re: [drakelist] AC-4R upgrades

Re: [drakelist] AC-4R upgrades

2006-12-14 Thread Tom Taylor
Hey, thanks for the tip! I just checked the vertical ceramic load resistor and it is open, just like yours. Last night I decided to just replace all the electrolytic capacitors under the chassis (and the diodes as well). Before clipping out the old parts, I took voltage measurements so I'd have a

Re: [drakelist] AC-4R upgrades

2006-12-14 Thread Dennis Monticelli
, December 12, 2006 5:27 AM To: Tom Taylor Cc: drakelist@www.zerobeat.net Subject: Re: [drakelist] AC-4R upgrades Donnie Garrett [EMAIL PROTECTED] made an utterance to the drakelist gang -- Tom: I have one of the early AC3 supplies

RE: [drakelist] AC-4R upgrades

2006-12-14 Thread Gerry
Garrett Sent: Tuesday, December 12, 2006 5:27 AM To: Tom Taylor Cc: drakelist@www.zerobeat.net Subject: Re: [drakelist] AC-4R upgrades Donnie Garrett [EMAIL PROTECTED] made an utterance to the drakelist gang -- Tom: I have one

Re: [drakelist] AC-4R upgrades

2006-12-14 Thread Donnie Garrett
Donnie Garrett [EMAIL PROTECTED] made an utterance to the drakelist gang -- Tom: I have one of the early AC3 supplies that used a HV choke. Garey K4OAH and I had a lot of discussions about its design some time back after I

Re: [drakelist] AC-4R upgrades

2006-12-14 Thread Garey Barrell
: drakelist@www.zerobeat.net Subject: Re: [drakelist] AC-4R upgrades Donnie Garrett [EMAIL PROTECTED] made an utterance to the drakelist gang -- Tom: I have one of the early AC3 supplies that used a HV choke. Garey K4OAH and I had

[drakelist] AC-4R upgrades

2006-12-12 Thread Tom Taylor
I have a number of Drake A, B, and C twin combos. I decided to upgrade all the power supplies with AC-4R boards. Since most of the caps are now 30 to 40 years old, I don't want to risk a bias supply going out and ruining the finals or some short ruining the transformers. I order a bunch of blank

Re: [drakelist] AC-4R upgrades

2006-12-11 Thread Garey Barrell
Garey Barrell [EMAIL PROTECTED] made an utterance to the drakelist gang -- Tom - Yeah, that's typical. You're taking the right approach, since a failure in the Bias supply can take out more than just the finals, even if the