RE: [drakelist] T-4XC permanent current problem
Ron Wagner <[EMAIL PROTECTED]> made an utterance to the drakelist gang -- Glad to know I am not the only one who thinks those stupid meter studs are a huge design error. The engineer on that one should be flogged. Of course it is likely the savings of 1 or 2 cents per unit that caused the original design to be redesigned by the "finance engineer". A short inside the meter. I never did like the way those meter studs were not fixed like others. Obviously in dismantling everything and re-assembling 73, Ron -- 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] T-4XC permanent current problem
Hi Martin, Glad you are making progress. When you are done, please come to North Carolina and finish my C-line for me HI. I learned a while ago that you may be able to get the crystal oscillator going again by simply replacing the oscillator transistor. This is certainly a lot less expensive than replacing the crystals. Give it a try, and let us know how it works. 73, Eric KA8FAN Martin Sole <[EMAIL PROTECTED]> wrote: "Martin Sole" <[EMAIL PROTECTED]>made an utterance to the drakelist gang--Found it.A short inside the meter. I never did like the way those meter studs werenot fixed like others. Obviously in dismantling everything and re-assemblingthe lug on the inside got rotated and was touching the inside of the metercase.Note to self: Don't unscrew the meter nuts to remove next time, unsolder thewires.All is good now but looks like the 20m and maybe the 80m crystals are dead.They will not oscillate in the transmitter nor in the receiver. Any crystalsfrom a dead radio out there?73Martin HS0ZED-Original Message-From: [EMAIL PROTECTED][mailto:[EMAIL PROTECTED] On Behalf Of Garey BarrellSent: 07 September 2005 04:13To: Martin SoleCc: 'drakelist'Subject: Re: [drakelist] T-4XC permanent current problemGarey Barrell <[EMAIL PROTECTED]>made an utterance to the drakelist gang--Martin -Something is shorting the final cathodes to ground, "South" of the metershunt, R59.There are a limited number of paths that can get the cathodes to ground,especially when that path has to handle the idle current you are seeing inthe "key-up" condition.Heater-cathode short in V7, (6AU6 AM Mod tube). ?I've never measured the key-up Final cathode voltage, but I think it couldrise as high as the screen voltage if the cathodes are "open" to ground?73, Garey - K4OAHAtlantaDrake C-Line Service ManualMartin Sole wrote:>"Martin Sole" <[EMAIL PROTECTED]>made an u! tterance to the drakelist >gang>-->I checked the bias voltage at the tube bases. The AC4 pot varies it >between about -44 volts and -85 volts. If I key the radio in SSB (No >Mic gain) and advance the bias pot until the meter shows 0.1A, bias >voltage measures about>-55 volts,then release the PTT the current increases to approximately0.12A.>>Same problem with different PA tubes that were known good last time >they were tried in another radio.>>Looking at the cathode line it seems this is taken to ground by a >contact on>K1 but when unkeyed should rise up to cut off the tubes. How many volts >should be on the cathode line in the unkeyed state? On this radio the >point at L5 sits around 0.38 volts in the unkeyed state and drops to >0.34 volts in the keyed state. Voltages are the same with K1 removed.>>Ideas appreciated.>>73>Martin HS0ZED>>>-Original Message->From: Gary Poland [mailto:[EMAIL PROTECTED]>Sent: 06 September 2005 10:22>To: Martin Sole>Subject: Re: [drakelist] T-4XC permanent current problem>>Martin,> Sounds like you have lost a capacitor in the AC-4 bias supply. The >voltage is too positive causing constant plate current.>>73, Gary>>>> >--Submissions: drakelist@www.zerobeat.netUnsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist inbodyHopelessly Lost: [EMAIL PROTECTED] - help in body of messageZerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.netNo virus found in th! is incoming message.Checked by AVG Anti-Virus.Version: 7.0.344 / Virus Database: 267.10.18/89 - Release Date: 02/09/2005-- No virus found in this incoming message.Checked by AVG Anti-Virus.Version: 7.0.344 / Virus Database: 267.10.18/89 - Release Date: 02/09/2005-- No virus found in this outgoing message.Checked by AVG Anti-Virus.Version: 7.0.344 / Virus Database: 267.10.18/89 - Release Date: 02/09/2005--Submissions: drakelist@www.zerobeat.netUnsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in bodyHopelessly Lost: [EMAIL PROTECTED] - help in body of messageZerobeat Web Page: www.zerobeat.net - sponsored by www.tlchost.net-- Click here to donate to the Hurricane Katrina relief effort.
RE: [drakelist] T-4XC permanent current problem
"Martin Sole" <[EMAIL PROTECTED]> made an utterance to the drakelist gang -- Found it. A short inside the meter. I never did like the way those meter studs were not fixed like others. Obviously in dismantling everything and re-assembling the lug on the inside got rotated and was touching the inside of the meter case. Note to self: Don't unscrew the meter nuts to remove next time, unsolder the wires. All is good now but looks like the 20m and maybe the 80m crystals are dead. They will not oscillate in the transmitter nor in the receiver. Any crystals from a dead radio out there? 73 Martin HS0ZED -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Garey Barrell Sent: 07 September 2005 04:13 To: Martin Sole Cc: 'drakelist' Subject: Re: [drakelist] T-4XC permanent current problem Garey Barrell <[EMAIL PROTECTED]> made an utterance to the drakelist gang -- Martin - Something is shorting the final cathodes to ground, "South" of the meter shunt, R59. There are a limited number of paths that can get the cathodes to ground, especially when that path has to handle the idle current you are seeing in the "key-up" condition. Heater-cathode short in V7, (6AU6 AM Mod tube). ? I've never measured the key-up Final cathode voltage, but I think it could rise as high as the screen voltage if the cathodes are "open" to ground? 73, Garey - K4OAH Atlanta Drake C-Line Service Manual <http://www.k4oah.com> Martin Sole wrote: >"Martin Sole" <[EMAIL PROTECTED]> made an utterance to the drakelist >gang >-- >I checked the bias voltage at the tube bases. The AC4 pot varies it >between about -44 volts and -85 volts. If I key the radio in SSB (No >Mic gain) and advance the bias pot until the meter shows 0.1A, bias >voltage measures about >-55 volts,then release the PTT the current increases to approximately 0.12A. > >Same problem with different PA tubes that were known good last time >they were tried in another radio. > >Looking at the cathode line it seems this is taken to ground by a >contact on >K1 but when unkeyed should rise up to cut off the tubes. How many volts >should be on the cathode line in the unkeyed state? On this radio the >point at L5 sits around 0.38 volts in the unkeyed state and drops to >0.34 volts in the keyed state. Voltages are the same with K1 removed. > >Ideas appreciated. > >73 >Martin HS0ZED > > >-Original Message- >From: Gary Poland [mailto:[EMAIL PROTECTED] >Sent: 06 September 2005 10:22 >To: Martin Sole >Subject: Re: [drakelist] T-4XC permanent current problem > >Martin, > Sounds like you have lost a capacitor in the AC-4 bias supply. The >voltage is too positive causing constant plate current. > >73, Gary > > > > > -- 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 -- -- No virus found in this incoming message. Checked by AVG Anti-Virus. Version: 7.0.344 / Virus Database: 267.10.18/89 - Release Date: 02/09/2005 -- No virus found in this incoming message. Checked by AVG Anti-Virus. Version: 7.0.344 / Virus Database: 267.10.18/89 - Release Date: 02/09/2005 -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.344 / Virus Database: 267.10.18/89 - Release Date: 02/09/2005 -- 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] T-4XC permanent current problem
Garey Barrell <[EMAIL PROTECTED]> made an utterance to the drakelist gang -- Martin - Something is shorting the final cathodes to ground, "South" of the meter shunt, R59. There are a limited number of paths that can get the cathodes to ground, especially when that path has to handle the idle current you are seeing in the "key-up" condition. Heater-cathode short in V7, (6AU6 AM Mod tube). ? I've never measured the key-up Final cathode voltage, but I think it could rise as high as the screen voltage if the cathodes are "open" to ground? 73, Garey - K4OAH Atlanta Drake C-Line Service Manual <http://www.k4oah.com> Martin Sole wrote: "Martin Sole" <[EMAIL PROTECTED]> made an utterance to the drakelist gang -- I checked the bias voltage at the tube bases. The AC4 pot varies it between about -44 volts and -85 volts. If I key the radio in SSB (No Mic gain) and advance the bias pot until the meter shows 0.1A, bias voltage measures about -55 volts,then release the PTT the current increases to approximately 0.12A. Same problem with different PA tubes that were known good last time they were tried in another radio. Looking at the cathode line it seems this is taken to ground by a contact on K1 but when unkeyed should rise up to cut off the tubes. How many volts should be on the cathode line in the unkeyed state? On this radio the point at L5 sits around 0.38 volts in the unkeyed state and drops to 0.34 volts in the keyed state. Voltages are the same with K1 removed. Ideas appreciated. 73 Martin HS0ZED -Original Message- From: Gary Poland [mailto:[EMAIL PROTECTED] Sent: 06 September 2005 10:22 To: Martin Sole Subject: Re: [drakelist] T-4XC permanent current problem Martin, Sounds like you have lost a capacitor in the AC-4 bias supply. The voltage is too positive causing constant plate current. 73, Gary -- 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] T-4XC permanent current problem
"Martin Sole" <[EMAIL PROTECTED]> made an utterance to the drakelist gang -- I checked the bias voltage at the tube bases. The AC4 pot varies it between about -44 volts and -85 volts. If I key the radio in SSB (No Mic gain) and advance the bias pot until the meter shows 0.1A, bias voltage measures about -55 volts,then release the PTT the current increases to approximately 0.12A. Same problem with different PA tubes that were known good last time they were tried in another radio. Looking at the cathode line it seems this is taken to ground by a contact on K1 but when unkeyed should rise up to cut off the tubes. How many volts should be on the cathode line in the unkeyed state? On this radio the point at L5 sits around 0.38 volts in the unkeyed state and drops to 0.34 volts in the keyed state. Voltages are the same with K1 removed. Ideas appreciated. 73 Martin HS0ZED -Original Message- From: Gary Poland [mailto:[EMAIL PROTECTED] Sent: 06 September 2005 10:22 To: Martin Sole Subject: Re: [drakelist] T-4XC permanent current problem Martin, Sounds like you have lost a capacitor in the AC-4 bias supply. The voltage is too positive causing constant plate current. 73, Gary -- No virus found in this incoming message. Checked by AVG Anti-Virus. Version: 7.0.344 / Virus Database: 267.10.18/89 - Release Date: 02/09/2005 -- No virus found in this incoming message. Checked by AVG Anti-Virus. Version: 7.0.344 / Virus Database: 267.10.18/89 - Release Date: 02/09/2005 -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.344 / Virus Database: 267.10.18/89 - Release Date: 02/09/2005 -- 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 --
