Re: [drakelist] L7 Voltage Sag
Al Parker [EMAIL PROTECTED] made an utterance to the drakelist gang -- Hi Neil, Sounds more like you need to be on 240 vac rather than 120. The input is sagging. 73, Al, W8UT New Bern, NC BoatAnchors appreciated here http://www.boatanchors.org http://www.hammarlund.info - Original Message - From: Neil Kutchera [EMAIL PROTECTED] To: drakelist@www.zerobeat.net Sent: Monday, March 27, 2006 7:27 AM Subject: [drakelist] L7 Voltage Sag Neil Kutchera [EMAIL PROTECTED] made an utterance to the drakelist gang -- I'm working on repairing my Drake L7 amplifier before I put it up for sale. It is set for 110 volts. When I turn on the amp the plate voltage reads either 2600 in SSB or 1850 in CW. Under load the it drops to 1000 volts regardless of the mode. The amp will run between 500 - 600 watts output with 120 watts of drive at this voltage. I've tested this with two sets of tubes. Does this indicate the power supply caps are in need of replacement? If so can anyone recommend a good source of parts? Thanks, Neil K4NJK -- Submissions:drakelist@www.zerobeat.net Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net -- -- Submissions:drakelist@www.zerobeat.net Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net --
RE: [drakelist] L7 Voltage Sag
[EMAIL PROTECTED] made an utterance to the drakelist gang -- It probably means you have #14 house wiring! Lee w0vt [Original Message] From: Neil Kutchera [EMAIL PROTECTED] To: drakelist@www.zerobeat.net Date: 03/27/2006 12:26:21 PM Subject: [drakelist] L7 Voltage Sag Neil Kutchera [EMAIL PROTECTED] made an utterance to the drakelist gang -- I'm working on repairing my Drake L7 amplifier before I put it up for sale. It is set for 110 volts. When I turn on the amp the plate voltage reads either 2600 in SSB or 1850 in CW. Under load the it drops to 1000 volts regardless of the mode. The amp will run between 500 - 600 watts output with 120 watts of drive at this voltage. I've tested this with two sets of tubes. Does this indicate the power supply caps are in need of replacement? If so can anyone recommend a good source of parts? Thanks, Neil K4NJK -- Submissions:drakelist@www.zerobeat.net Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net -- -- Submissions:drakelist@www.zerobeat.net Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net --
Re: [drakelist] L7 Voltage Sag
Based upon 30+ years of experience with L4, L4B, L7 amps, wired for 110v and 220v, in multiplelocations, I would bet aStarbuck's coffee that the problemwith that great of a voltage sag is due to one or more electrolytic capacitors failing. For the secondary to sag by 40-50% due to a primary(linevoltage) sag, that means the line voltage would go down to 55-60 VAC. So, any bets? 73, Evan-Original Message-From: [EMAIL PROTECTED]To: Neil Kutchera [EMAIL PROTECTED]; drakelist@www.zerobeat.netSent: Mon, 27 Mar 2006 15:44:37 -0600Subject: RE: [drakelist] L7 Voltage Sag "" [EMAIL PROTECTED] made an utterance to the drakelist gang -- It probably means you have #14 house wiring! Lee w0vt [Original Message] From: Neil Kutchera [EMAIL PROTECTED] To: drakelist@www.zerobeat.net Date: 03/27/2006 12:26:21 PM Subject: [drakelist] L7 Voltage Sag Neil Kutchera [EMAIL PROTECTED] made an utterance to the drakelist gang -- I'm working on repairing my Drake L7 amplifier before I put it up for sale. It is set for 110 volts. When I turn on the amp the plate voltage reads either 2600 in SSB or 1850 in CW. Under load the it drops to 1000 volts regardless of the mode. The amp will run between 500 - 600 watts output with 120 watts of drive at this voltage. I've tested this with two sets of tubes. Does this indicate the power supply caps are in need of replacement? If so can anyone recommend a good source of parts? Thanks, Neil K4NJK -- Submissions:drakelist@www.zerobeat.net Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net -- -- Submissions:drakelist@www.zerobeat.net Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net --
Re: [drakelist] L7 Voltage Sag
Garey Barrell [EMAIL PROTECTED] made an utterance to the drakelist gang -- Evan - I think you have the right idea. Sounds like one or more caps with a high ESR. They charge up fine with just the bleeder load, but as soon as you draw any real current the voltage sags to about 1/2. The other key, as I read the original question was that BOTH voltages drop to about 1000 V, or ~1300 and ~ 950? Add that the to fact that if they are original those caps are past their expected lifetime. I bet an ESR meter would show the problem. 73, Garey - K4OAH Atlanta Drake B C-Line Service CDs http://www.k4oah.com [EMAIL PROTECTED] wrote: Based upon 30+ years of experience with L4, L4B, L7 amps, wired for 110v and 220v, in multiple locations, I would bet a Starbuck's coffee that the problem with that great of a voltage sag is due to one or more electrolytic capacitors failing. For the secondary to sag by 40-50% due to a primary (line voltage) sag, that means the line voltage would go down to 55-60 VAC. So, any bets? 73, Evan -Original Message- From: [EMAIL PROTECTED] To: Neil Kutchera [EMAIL PROTECTED]; drakelist@www.zerobeat.net Sent: Mon, 27 Mar 2006 15:44:37 -0600 Subject: RE: [drakelist] L7 Voltage Sag [EMAIL PROTECTED] mailto:pulsarxp%40earthlink.net made an utterance to the drakelist gang -- It probably means you have #14 house wiring! Lee w0vt [Original Message] From: Neil Kutchera [EMAIL PROTECTED] mailto:k4njk%40bellsouth.net To: drakelist@www.zerobeat.net mailto:drakelist%40www.zerobeat.net Date: 03/27/2006 12:26:21 PM Subject: [drakelist] L7 Voltage Sag Neil Kutchera [EMAIL PROTECTED] mailto:k4njk%40bellsouth.net made an utterance to the drakelist gang -- I'm working on repairing my Drake L7 amplifier before I put it up for sale. It is set for 110 volts. When I turn on the amp the plate voltage reads either 2600 in SSB or 1850 in CW. Under load the it drops to 1000 volts regardless of the mode. The amp will run between 500 - 600 watts output with 120 watts of drive at this voltage. I've tested this with two sets of tubes. Does this indicate the power supply caps are in need of replacement? If so can anyone recommend a good source of parts? Thanks, Neil K4NJK -- Submissions:drakelist@www.zerobeat.net Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net --
Re: [drakelist] L7 Voltage Sag
Dennis Monticelli [EMAIL PROTECTED] made an utterance to the drakelist gang -- I'm going with the flow and say bad caps. I have a recapped L7 here in the shack running off 120V at the end of a long run thru the house. I typically load it to 400 or 500W on the CW (lower HV) setting with at most 50W of drive. While I haven't measured the line sag, I would guess it runs 5 to 10V judging by the slight dimming of the lights. BTW, a slow turning fan placed on top of the power supply cage does wonders for drawing out heat and probably increasing longevity in the process. Dennis AE6C On 3/27/06, Garey Barrell [EMAIL PROTECTED] wrote: Garey Barrell [EMAIL PROTECTED] made an utterance to the drakelist gang -- Evan - I think you have the right idea. Sounds like one or more caps with a high ESR. They charge up fine with just the bleeder load, but as soon as you draw any real current the voltage sags to about 1/2. The other key, as I read the original question was that BOTH voltages drop to about 1000 V, or ~1300 and ~ 950? Add that the to fact that if they are original those caps are past their expected lifetime. I bet an ESR meter would show the problem. 73, Garey - K4OAH Atlanta Drake B C-Line Service CDs http://www.k4oah.com [EMAIL PROTECTED] wrote: Based upon 30+ years of experience with L4, L4B, L7 amps, wired for 110v and 220v, in multiple locations, I would bet a Starbuck's coffee that the problem with that great of a voltage sag is due to one or more electrolytic capacitors failing. For the secondary to sag by 40-50% due to a primary (line voltage) sag, that means the line voltage would go down to 55-60 VAC. So, any bets? 73, Evan -Original Message- From: [EMAIL PROTECTED] To: Neil Kutchera [EMAIL PROTECTED]; drakelist@www.zerobeat.net Sent: Mon, 27 Mar 2006 15:44:37 -0600 Subject: RE: [drakelist] L7 Voltage Sag [EMAIL PROTECTED] mailto:pulsarxp%40earthlink.net made an utterance to the drakelist gang -- It probably means you have #14 house wiring! Lee w0vt [Original Message] From: Neil Kutchera [EMAIL PROTECTED] mailto:k4njk%40bellsouth.net To: drakelist@www.zerobeat.net mailto:drakelist%40www.zerobeat.net Date: 03/27/2006 12:26:21 PM Subject: [drakelist] L7 Voltage Sag Neil Kutchera [EMAIL PROTECTED] mailto:k4njk%40bellsouth.net made an utterance to the drakelist gang -- I'm working on repairing my Drake L7 amplifier before I put it up for sale. It is set for 110 volts. When I turn on the amp the plate voltage reads either 2600 in SSB or 1850 in CW. Under load the it drops to 1000 volts regardless of the mode. The amp will run between 500 - 600 watts output with 120 watts of drive at this voltage. I've tested this with two sets of tubes. Does this indicate the power supply caps are in need of replacement? If so can anyone recommend a good source of parts? Thanks, Neil K4NJK -- Submissions:drakelist@www.zerobeat.net Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net -- -- Submissions:drakelist@www.zerobeat.net Unsubscribe:[EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost:[EMAIL PROTECTED] - help in body of message Zerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net --
