Re: [drakelist] 2nt with a r-4c need a sidetone
The 2-NT manual, page 2, shows a schematic of hooking up the 2-NT with an R-4A. I assume hooking up to the R-4C would be something similar. Unfortunately, it is not exactly plug'n'play. The diagram shows the 2-NT's sidetone cable connecting "To Pins 2 or 5 of V7, 6EH5 or to arm of AF Gain Control". I guess it would be different on a R-4C because the R-4C has a solid-state audio amp compared with the tube driven audio of the R-4A. Perhaps connecting to the arm of the AF Gain Control is still valid. Tom N7TM On 2/1/07, Frank <[EMAIL PROTECTED]> wrote: Can someone tell me --The sidetone cable from a 2nt goes to where on a r-4c Thanks Frank wa2aaw
Re: [drakelist] Drake 2-NT to Heath HG-10B VFO Interface
I ran the output from the HG-10B's phono jack through 2' piece of rg-58 coax to an old crystal holder. I took a non-ham band crystal, unscrewed the metal plate, took out the crystal, drilled a hole in the end for the coax, soldered the wires, and put the plate back on. It looks neat and makes it easy to switch between the vfo and a regular xtal. On my setup, the key plugs into the 2-NT and the 2-NT keys the HG-10B. Seems to work fine. Tom N7TM On 1/26/07, Dino Papas <[EMAIL PROTECTED]> wrote: Dino Papas <[EMAIL PROTECTED]> made an utterance to the drakelist gang -- Has anyone done this interface along the lines recommended by Roy Vickers KF5YU described at: http://www.zerobeat.net/drakelist/2nt-hg10.html Roy changes the VFO signal routing by connecting the VFO RF output from the phono jack on the rear panel thru the interface cable he built that plugs into the octal socket which eventually ends up at the 2-NT crystal socket. What I'm wondering about is the fact that doing so routes the RF along a single wire vs. a coax cable as originally configured. At least it didn't look like he did that with coax. It may very well be that it's no problem but just thought I'd check before surgery. My gut feeling is to at least do it with a piece of RG-174 to keep that signal as clean as possible. Love these "retro projects" that take us back to our childhood ham radio days! Thanks in advance! Dino KL0S/4 -- 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] MN-2000 Paint
My MN-2000 with original paint has the rough surface paint. Tom N7TM On 1/22/07, Mike Rowlands <[EMAIL PROTECTED]> wrote: While we are talking about Drake paint finishes, would somebody please confirm that MN-2000 was originally shipped with a smooth finish? Thanks, Mike VA3MR/G3NKR
Re: [drakelist] TR-3 Paint
The paint on my TR-3 is smooth, too. The cabinet definitely does *not* look like it's been repainted. Tom n7tm On 1/19/07, LeMoine Family <[EMAIL PROTECTED]> wrote: "LeMoine Family" <[EMAIL PROTECTED]> made an utterance to the drakelist gang -- My TR-3's paint is smooth. 73, Dave KV4CN - Original Message - From: "Ken" <[EMAIL PROTECTED]> To: Sent: Friday, January 19, 2007 7:39 AM Subject: [drakelist] TR-3 Paint > > "Ken" <[EMAIL PROTECTED]> made an utterance to the drakelist gang > -- > > Easy question...What is the paint type on the TR-3 case -Is it 'bumpy' > like the -4 series, or smooth? Tnx! > > Ken ACØDQ > > -- > 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] AC-4R upgrades
I lifted the 220k bleeder from ground and it measured about 230k, probably not enough of a change to account for such a high voltage. I soldered the bleeder back to ground and untied the connection between the 10k 25w load resistor between the HV and 250v supply. The 250v supply now reads a reasonable 270v while the HV rises out of control (+900v). Reconnecting that 10k back to the 250v supply, the 250v reads over 500v. I don't "get" how that 10k load resistor is supposed to work? It would make more sense to me if it was tied to ground, but the only way it's getting to ground is through the puny 220k 1/2w resistor on the 250v supply. Tom On 1/15/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote: 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 in value over time. Those resistors are known to do that. -- Original message -- From: "Ken Winterling" <[EMAIL PROTECTED]> > > "Ken Winterling" 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 HV. Let us know what you find. > > Ken, WA2LBI > > > > On 1/14/07, Tom Taylor wrote: > > > Still working on the AC-3... The drakelist wisdom was the 20k load resistor > > > didn't present enough of a load, compared to the original 10k resistor, and > > > that was the reason the HV kept climbing. I ordered a 10k 10w re sistor and > > > it recently arrived and I installed it in place. Note that this resistor > > > connects the HV+ with the medium voltage B+ (which seems odd). With this new > > > resistor, the HV now reads a reasonable and respectable 720v (no load). > > > That's good. But the medium voltage now reads 570v !!! I can't explain it. > > > What's different about the medium voltage supply is I replaced the two 100 > > > uf caps with 330 uf caps and the 80 uf cap with a 120 uf. That's what I had > > > in my junk box. Why is that supply so over-voltage now? Perhaps I have a > > > wiring error, though I carefully checked for errors. > > > > > > Thanks, > > > Tom n7tm > > > > > > -- > Submissions: drakelist@www.zerobeat.net > Unsubscribe: m [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] AC-4R upgrades
Still working on the AC-3... The drakelist wisdom was the 20k load resistor didn't present enough of a load, compared to the original 10k resistor, and that was the reason the HV kept climbing. I ordered a 10k 10w resistor and it recently arrived and I installed it in place. Note that this resistor connects the HV+ with the medium voltage B+ (which seems odd). With this new resistor, the HV now reads a reasonable and respectable 720v (no load). That's good. But the medium voltage now reads 570v !!! I can't explain it. What's different about the medium voltage supply is I replaced the two 100 uf caps with 330 uf caps and the 80 uf cap with a 120 uf. That's what I had in my junk box. Why is that supply so over-voltage now? Perhaps I have a wiring error, though I carefully checked for errors. Thanks, Tom n7tm On 12/20/06, Tom Taylor <[EMAIL PROTECTED]> wrote: I replaced the diodes and capacitors in the early AC-3 w/choke power supply. I used what I had on hand. The HV caps, originally 350v 80 uf, are now 450v 120 uf. The 10k HV load resistor was open. I replaced it with what I had, a 20k 50w resistor. While testing the refurbished supply last Thursday night, the Northwest was hit with a terrific wind storm and our power was knocked out at that instant. We're on our eigth day without power at home (have power and internet here at work). I've posted pictures of the trees and power lines here: http://www.advrider.com/forums/showthread.php?t=189994&highlight=northwest+wind+storm Unfortunately, the HV exhibits the behavior you mentioned in your reply. While measuring the HV on power up, the voltage quickly climbs to 850v, then continues to climb at a slower rate to over 900v. At 920v (past the voltage limit of the two series caps), I pulled the plug. Is the fact that the voltage is climbing so high not under load indicating that my load resistor is not loading the HV enough? The old value was 10k, the new value is 20k. With values that high, I figured it wouldn't matter much, but perhaps it does. I have a couple comments after converting several AC-3's and AC-4's to use the AC-4R replacement board: - the supplies really did change over the years. One example, my "newest" AC-4 has a 120/220v switch and a 3 wire plug, but none of the others do - I'm surprised by the very small gauge wires in the wire bundle supplying the xmtr. That HV wire is so thinly insulated -- no more so than any of the other wires. Has anyone else converted an AC-3 (the non-choke model) to use the AC-4R board? I mounted the board on standoffs on top of the chassis. I'd hate to reach around the back of an MS-4 enclosure to adjust the bias pot (which is on top of the AC-3 chassis) and touch the open AC-4R board. There's some serious voltage -- and a lot of stored energy with the new caps -- right there. Has anyone built a little cage around the board? Seems like a lot of work, but perhaps worth it. Tom n7tm On 12/12/06, Gerry <[EMAIL PROTECTED]> wrote: > > What you describe is typical of choke input power supplies. Text books > tell > us that choke input supplies are better at regulation but that is simply > not > true if you have a wide ranging dynamic load. Choke input power supplies > > require a minimum load. There are formulas in the old handbooks to > calculate > the value of resistance to draw a proper load current. Without a minimum > load it would be as if no choke existed (except for its DC resistance) > and > the filter capacitors will charge to 1.414 times the value of AC rms. In > other words, if you have 750VAC secondary the capacitors will charge to > over > 1,060 volts with no load! With a properly chosen resistor this would be > 0.9 > times 750 volts or 675 volts. Please note the HV filter capacitors are > only > rated to 350 volts for a total of only 700 volts. So as you can see, the > 10k, 20w load resistor on the output of the HV side of the supply is > crucial. That resistor dissipates around 16 watts. Notice that the low > end > is referenced to +250V and not ground. It should be rated for twice the > actual power dissipation or 32 watts. Put it another way, without the > load > resistor, key up voltage would be around 1kV while key down would drop > to > about 675 volts. I should mention that the choke has DC resistance which > may > be a significant contributor to voltage drop. If you draw 450 mils and > your > DC choke has 50 Ohms of DC resistance, you will drop an additional 22.5 > volts across the choke. Also look at the +250 volt side and see that the > filter caps are rated to only 300 volts. This is much too close for > comfort > and is really a very slim margin of safety. Typically the voltage rating > of > electrolytics is related to the maximum voltage it can withstand for a > given >
Re: [drakelist] HELP!
Hey Garey, Perhaps I can help. I have a TR-4 s/n 19651. The accompanying manual (original, not a copy) has no schematic number on it underneath the block letters "SCHEMATIC DIAGRAM MODEL TR-4 TRANSCEIVER". Perhaps it's older than the numbering system used on later manuals. Another TR-4 s/n 31985 has a manual with a number of 15672600. Maybe that corresponds to 1/5/67. It's 50/50 that the manuals aren't the originals that came with the rigs. But that doesn't matter of course, if you're simply looking for early editions of the schematic. You're welcome to borrow both manuals if they contain the schematic you're looking for. Tom n7tm On 1/1/07, Garey Barrell <[EMAIL PROTECTED]> wrote: Garey Barrell <[EMAIL PROTECTED]> made an utterance to the drakelist gang -- I need a little help. I'm working (still !) on the TR-4 Series CD, and there appears to be yet another version schematic or two, other than the eight I already have. All my usual sources have come up dry, including Drake, which had only TWO of the eight known versions. The earliest TR-4 schematic I have is 256619500, which translates to 2/5/66, s/n 19500 and up. The _First_ TR-4 schematic would be sometime in 1965, probably around s/n 15000. That is the one I am looking for. The earliest TR-4C schematic I have is 3147435161, which translates to 3/14/74, s/n 35161 and up. The _First_ TR-4_C_ schematic would be sometime in 1972, probably around s/n 32000. That is the one I am looking for. It's possible that there are one or more additional versions between 32000 and 35160, but I'd be happy to find just the one around 32000! SO ! If anyone with an _original_ Drake TR-4 or TR-4C manual would check the version number on the schematic, I would very much like to find one or both to include in the CD. The first person who comes up with an original for loan or purchase of either or both of these "missing links" will be entitled to a free Drake Service Supplement CD. Thanks for looking! -- 73, Garey - K4OAH Atlanta Drake 2-B, 4-B & C-Line Service Supplement CDs -- 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] AC-4R upgrades
I replaced the diodes and capacitors in the early AC-3 w/choke power supply. I used what I had on hand. The HV caps, originally 350v 80 uf, are now 450v 120 uf. The 10k HV load resistor was open. I replaced it with what I had, a 20k 50w resistor. While testing the refurbished supply last Thursday night, the Northwest was hit with a terrific wind storm and our power was knocked out at that instant. We're on our eigth day without power at home (have power and internet here at work). I've posted pictures of the trees and power lines here: http://www.advrider.com/forums/showthread.php?t=189994&highlight=northwest+wind+storm Unfortunately, the HV exhibits the behavior you mentioned in your reply. While measuring the HV on power up, the voltage quickly climbs to 850v, then continues to climb at a slower rate to over 900v. At 920v (past the voltage limit of the two series caps), I pulled the plug. Is the fact that the voltage is climbing so high not under load indicating that my load resistor is not loading the HV enough? The old value was 10k, the new value is 20k. With values that high, I figured it wouldn't matter much, but perhaps it does. I have a couple comments after converting several AC-3's and AC-4's to use the AC-4R replacement board: - the supplies really did change over the years. One example, my "newest" AC-4 has a 120/220v switch and a 3 wire plug, but none of the others do - I'm surprised by the very small gauge wires in the wire bundle supplying the xmtr. That HV wire is so thinly insulated -- no more so than any of the other wires. Has anyone else converted an AC-3 (the non-choke model) to use the AC-4R board? I mounted the board on standoffs on top of the chassis. I'd hate to reach around the back of an MS-4 enclosure to adjust the bias pot (which is on top of the AC-3 chassis) and touch the open AC-4R board. There's some serious voltage -- and a lot of stored energy with the new caps -- right there. Has anyone built a little cage around the board? Seems like a lot of work, but perhaps worth it. Tom n7tm On 12/12/06, Gerry <[EMAIL PROTECTED]> wrote: What you describe is typical of choke input power supplies. Text books tell us that choke input supplies are better at regulation but that is simply not true if you have a wide ranging dynamic load. Choke input power supplies require a minimum load. There are formulas in the old handbooks to calculate the value of resistance to draw a proper load current. Without a minimum load it would be as if no choke existed (except for its DC resistance) and the filter capacitors will charge to 1.414 times the value of AC rms. In other words, if you have 750VAC secondary the capacitors will charge to over 1,060 volts with no load! With a properly chosen resistor this would be 0.9 times 750 volts or 675 volts. Please note the HV filter capacitors are only rated to 350 volts for a total of only 700 volts. So as you can see, the 10k, 20w load resistor on the output of the HV side of the supply is crucial. That resistor dissipates around 16 watts. Notice that the low end is referenced to +250V and not ground. It should be rated for twice the actual power dissipation or 32 watts. Put it another way, without the load resistor, key up voltage would be around 1kV while key down would drop to about 675 volts. I should mention that the choke has DC resistance which may be a significant contributor to voltage drop. If you draw 450 mils and your DC choke has 50 Ohms of DC resistance, you will drop an additional 22.5 volts across the choke. Also look at the +250 volt side and see that the filter caps are rated to only 300 volts. This is much too close for comfort and is really a very slim margin of safety. Typically the voltage rating of electrolytics is related to the maximum voltage it can withstand for a given numbers of hours at some temperature. Component manufacturers usually try to embellish the specifications and say their caps will take 1000 hours of use at room temperature. But in actual operation ambient temperature will be higher than 25 degrees C and they typically don't say too much about self heating due to ripple current which brings up temperature even more. This is why it is always best to over rate voltage in electrolytics when selecting components. I see that Drake realized this was not a good design and soon changed to a capacitive input supply which is better suited to SSB service, and less expensive. As far as I'm concerned I would avoid the original AC-3 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 "Donnie Garrett" <[EMAIL PROTECTED]> made an utterance to the drakelist gang ---
Re: [drakelist] AC-4R upgrades
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 baseline to test against after replacing the capacitors. The HV seemed unusually high at 854 vdc. The open load resistor probably explains that very HV. Thanks, Tom On 12/12/06, Donnie Garrett <[EMAIL PROTECTED]> wrote: 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 discovered the ceramic 25W load resistor was open. You better check yours to see if its OK. It will still operate but the no load HV will float very high with an open load resistor. I was never able to find an exact replacement at the time I needed it so I installed a 25W wire-wound resistor in a vertical fashion with a small bolt running through it. Somewhat similar to the original setup. I choose a 25K 25W instead of a 15K to reduce the heat dissipation produced by the resistor. The 25K still loaded down the HV and was near the same as was prior with the original 15K 25W resistor which seems to regularly fail due to running it at or near it's maxium wattage dissipation. Also one last thing, If I recall the HV winding on this early choke version AC3 was higher than the later AC3 and AC4's that didn't use the HV choke. Seems I temporally jumped across this choke just to see what effect it had on the HV and if I recall correctly the HV jumped up in voltage considerably, and was then out of speck and was near the max voltage ratings of the 2 HV caps. (No Good) I would appreciate your findings on the HV secondary windings if you don't mind. Too put it quite frankly I don't care for the early model AC3 choke type supply due to these issues. The only nice thing about this model is that all the caps mount on the underside of its chassis. This AC3 supply now serves as my test bench supply and is not used in my station. Hope this helps, Don / WA9TGT On 12/11/06, Tom Taylor <[EMAIL PROTECTED]> wrote: > 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 boards since I already had some of the parts. The rest of the parts I ordered from DigiKey. I assembled all the boards at the same time and then started upgrading the AC-4s, one by one. > > So far, all of the power supplies are different in one way or another and all of them have been modified by previous owners. Here are some examples: > > #1) A previous owner replace the mid-voltage supplies' capacitors with a bundle of three caps mounted to the upper end the supply. > > #2) A previous owner replaced the sand resistor below the chassis with two higher wattage resistors mounted to the upper end of the supply. > > #3) A previous owner replaced one of the diodes in the HV supply. The transformer in this supply has transformer bolts inserted the wrong direction to mount the AC-4R board. Unfortunately, it's not as simple as removing the bolts and inserting them in the other direction because the bolts are just long enough to reach, but not long enough to add the board spacers. > > #4) This is an AC-3, serial #101. I've never seen a Drake power supply like this. There's a large choke mounted adjacent to the transformer. All of the other parts, including the capacitors, are radial lead caps that are packed underneath the very low chassis. Has anyone else seen an early AC-3 like this? I'm planning to remove the choke and rebuilding the supply just like all of the others since all of the circuitry is now on the AC-4R board. > > Thanks, > Tom N7TM > -- WA9TGT / Don Garrett / Muncie, IN "Unique Radio Parts" www.wa9tgt.com
[drakelist] AC-4R upgrades
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 boards since I already had some of the parts. The rest of the parts I ordered from DigiKey. I assembled all the boards at the same time and then started upgrading the AC-4s, one by one. So far, all of the power supplies are different in one way or another and all of them have been modified by previous owners. Here are some examples: #1) A previous owner replace the mid-voltage supplies' capacitors with a bundle of three caps mounted to the upper end the supply. #2) A previous owner replaced the sand resistor below the chassis with two higher wattage resistors mounted to the upper end of the supply. #3) A previous owner replaced one of the diodes in the HV supply. The transformer in this supply has transformer bolts inserted the wrong direction to mount the AC-4R board. Unfortunately, it's not as simple as removing the bolts and inserting them in the other direction because the bolts are just long enough to reach, but not long enough to add the board spacers. #4) This is an AC-3, serial #101. I've never seen a Drake power supply like this. There's a large choke mounted adjacent to the transformer. All of the other parts, including the capacitors, are radial lead caps that are packed underneath the very low chassis. Has anyone else seen an early AC-3 like this? I'm planning to remove the choke and rebuilding the supply just like all of the others since all of the circuitry is now on the AC-4R board. Thanks, Tom N7TM
Re: [drakelist] AC-4R upgrades
Would I be destroying something of historical worth by converting that early, and perhaps rare AC-3, to a modern supply? That would mean removing the choke and essentially all the parts underneath the chassis? The AC-4R (as I'm sure you're aware) replaces everything but the transformer, the cables, the connectors, and the bias pot. On 12/11/06, Garey Barrell <[EMAIL PROTECTED]> wrote: 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 unit is in Standby. #4. Yes, this is a VERY early AC-3. I don't know how many were made, but I've only seen a couple in 40 years of using/working on Drake gear. They work just fine, but your plan is reasonable. Drake dropped the choke, probably for cost / weight / not needed reasons. The primary reason for it originally was to improve the regulation of the HV. 73, Garey - K4OAH Atlanta Drake 2-B, 4-B & C-Line Service Supplement CDs Tom Taylor wrote: > 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 boards since I already had some of the parts. The > rest of the parts I ordered from DigiKey. I assembled all the boards > at the same time and then started upgrading the AC-4s, one by one. > > So far, all of the power supplies are different in one way or another > and all of them have been modified by previous owners. Here are some > examples: > > #1) A previous owner replace the mid-voltage supplies' capacitors with > a bundle of three caps mounted to the upper end the supply. > > #2) A previous owner replaced the sand resistor below the chassis with > two higher wattage resistors mounted to the upper end of the supply. > > #3) A previous owner replaced one of the diodes in the HV supply. The > transformer in this supply has transformer bolts inserted the wrong > direction to mount the AC-4R board. Unfortunately, it's not as simple > as removing the bolts and inserting them in the other direction > because the bolts are just long enough to reach, but not long enough > to add the board spacers. > > #4) This is an AC-3, serial #101. I've never seen a Drake power supply > like this. There's a large choke mounted adjacent to the transformer. > All of the other parts, including the capacitors, are radial lead caps > that are packed underneath the very low chassis. Has anyone else seen > an early AC-3 like this? I'm planning to remove the choke and > rebuilding the supply just like all of the others since all of the > circuitry is now on the AC-4R board. > > Thanks, > Tom N7TM
Re: [drakelist] AC-4 Relay Plug
Here's how I homebrewed an AC-4 relay connector: http://www.zerobeat.net/drakelist/voxrelayplug.html Tom On 11/29/06, Clair Truax <[EMAIL PROTECTED]> wrote: Clair Truax <[EMAIL PROTECTED]> made an utterance to the drakelist gang -- Could someone point me to a source for the little two-pole relay plug for the back of the AC-4 power supply, which I use to key an amplifier? At present I am just inserting wires into it and taping it in place with duct tape, not an elegant way to do it, but it works! CUL, CLAIR KJ6NJ ___ Borrego Springs, California 92004 -- 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] Drake 2-C and stingy s-meter
Just got some time to look at the 2-C again and go through all the suggestions.I swapped V4 with a NOS 12BE6. It made no difference to the s-meter.Thanks for the clarifications on the resistances around V3. My 2-C is #2804, well past the changes made at #1000. I measured the DC voltage at C48: 10.1v. Seems very low.TomOn 10/12/06, Garey Barrell < [EMAIL PROTECTED]> wrote:Tom -OK. Next try V4. It, and V1 are controlled by the AGC #2 and are the "other side" of the S-Meter bridge.Your readings on V3 (I'm assuming you're referring to Pin 2, not Pin 3)reflect a circuit change. There are at least two versions of the 2-Cthat I'm familiar with, and the voltage/resistance charts weren't updated to reflect the later version. Version 2 started at s/n 1000.Your readings are correct for Version 2 units.The AF collector voltage seems too low. A leaky Q6 can cause this.What is the voltage at the top of C48? (The +12V power supply filter cap) 73, Garey - K4OAHAtlantaDrake 2-B, 4-B & C-Line Service CDs<www.k4oah.com>Tom Taylor wrote:> I tried swapping several 12BA6's (V5) at Garey's suggestion. All > caused me to recalibrate the s-meter zero and I was able to get -13v> at tp-1, but the s-meter is nearly unreponsive. It'll register S4 on> only the very strongest of signals. I replaced the 12BZ6 with a NOS > tube and that had no positive effect on the s-meter either.>> I did a voltage and resistance check against the table in the manual> just to see if there was anything way off. Surprisingly, the case of > the output transistor was at 10.3v instead of 12.5v. Perhaps that's> why audio isn't ear blasting. I'll have to investigate further. As far> as the resistance checks, everything was within reason for a 35 year > old (perhaps older) radio, except for the resistances around V3, the> mixer and VFO. Pin 3 is supposed to be 330 ohms and I measure .6 ohms.> Pin 7 is supposed to be 7k and I measure 1m. Should I believe the > chart in the manual? The VFO certainly seems to work fine. With those> measurements so far off, I wouldn't expect the receiver to be so> operational, except for the S-meter.>> I guess I'll dive deeper and try and understand why those couple > resistance measurements are so far from what's listed in the chart.>> Tom n7tm>>
Re: [drakelist] Drake 2-C and stingy s-meter
I tried swapping several 12BA6's (V5) at Garey's suggestion. All caused me to recalibrate the s-meter zero and I was able to get -13v at tp-1, but the s-meter is nearly unreponsive. It'll register S4 on only the very strongest of signals. I replaced the 12BZ6 with a NOS tube and that had no positive effect on the s-meter either. I did a voltage and resistance check against the table in the manual just to see if there was anything way off. Surprisingly, the case of the output transistor was at 10.3v instead of 12.5v. Perhaps that's why audio isn't ear blasting. I'll have to investigate further. As far as the resistance checks, everything was within reason for a 35 year old (perhaps older) radio, except for the resistances around V3, the mixer and VFO. Pin 3 is supposed to be 330 ohms and I measure .6 ohms. Pin 7 is supposed to be 7k and I measure 1m. Should I believe the chart in the manual? The VFO certainly seems to work fine. With those measurements so far off, I wouldn't expect the receiver to be so operational, except for the S-meter. I guess I'll dive deeper and try and understand why those couple resistance measurements are so far from what's listed in the chart.Tom n7tmOn 10/11/06, Jason Buchanan <[EMAIL PROTECTED]> wrote: Tom Taylor wrote:> The receiver receives well, but the S-meter is extremely stingy. A> very loud SW broadcast station may only read S5.>Will be interested to hear what you find out... I have an R-4 that exhibits the same on its S meter. It receives fine but with max CCW theneedle reads about +50dB. I went back and recalibrated it as it shouldbe which made the AGC sound as a Drake should. If the recv sens or S meter sens is off you will not have the best sounding AGC action (thumpy).One other thing to try is replacing the 12BZ6. If it's weak the dynamicrange will be low.thanks--73 Jason N1SU Jason Buchanan - Boxboro, MAWebsite: http://n1su.com/
[drakelist] Drake 2-C and stingy s-meter
My 2-C receiver became deaf after a couple of months of not turning it on. I took the covers off and carefully deoxit'd the bandswitch and other wafers. That didn't have any effect. Then I wiggled each tube and found a culprit. I deoxit'd the tube sockets and that did the trick. I've never aligned this receiver and so I went through the alignment procedure in the manual. The 50 khz (or kc, as the manual says) and the 455 kc xfmrs needed slight tweaking to bring them exactly on frequency. The last step is calibrating the s-meter. At - 1.35v, the meter is set to S1. Then backing off the RF gain to -13v, the meter is checked for S9+40. With the RF gain turned all the way down, I could only read about -11.5v. In any case, the S meter read close to S9+40 and I called it good. The receiver receives well, but the S-meter is extremely stingy. A very loud SW broadcast station may only read S5.Any ideas or suggestions what's wrong that my cause the meter to be so unresponsive? Thanks,Tom n7tm
Re: [drakelist] Newbie with questions.
Is there a way to know when the bias supply has died? Suppose you're sitting in front of the radio, it appears to be operating normally, and then the bias suddenly disappears (i.e. diode opens, cap goes out, etc.). At this point, you're simply listening to the receiver. What indication would you get on the xmtr other than the 6JB6's (or 12JB6's for TR-3's) turning red hot? It sounds like we need a klaxon alarm wired to the bias :-) Tom n7tm
RE: [drakelist] dirty bandswitches - how to fix?
I guess I’ve been really careless with my use of DeOxit because I haven’t been careful at all when spraying the various wafers of the switches underneath. Perhaps I’ve taken decades off the long term life of the radios, but in the past ten years, I haven’t noticed any degradation. Ten years ago someone sold me an old TR-3 for $25. It was really dirty and disgusting to work on so I ended up running it through a cycle in the dishwasher and then letting it dry in the sun. It certainly came out a lot cleaner and after fixing the few problems it had before cleaning it, it has worked fine for the past ten years. On the down side, that first TR-3 was the catalyst that re-kindled my interest in Drakes from my days as a youth and a novice (WN8RUO). Tom N7TM
RE: [drakelist] crystal sockets
"Tom Taylor \(MSTV\)" <[EMAIL PROTECTED]> made an utterance to the drakelist gang -- What I do is take an old non-ham-band crystal of the correct size and unscrew the little top cover plate. I remove the old crystal inside and then solder the new, but much smaller crystal inside to the pins. Then I screw the cover plate back on the crystal and I'm good to go. Occasionally I'll have to use a Dremel to route out the interior of the crystal holder to make room for the "crystal within a crystal." Tom N7TM -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jason Buchanan Sent: Saturday, November 26, 2005 19:16 PM To: drakelist@zerobeat.net Subject: [drakelist] crystal sockets Jason Buchanan <[EMAIL PROTECTED]> made an utterance to the drakelist gang -- hi, I have a couple crystals that i'd like to put into use but they're the small size with legs about 1/4" inch apart. Just wondering if there are any adapters out there to fit these small crystals into or if there's a way to do this another way. thanks 73 Jason N1SU -- 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] Re: T-4XC sidetone
"Tom Taylor \(MSTV\)" <[EMAIL PROTECTED]> made an utterance to the drakelist gang -- Speaking of Drake compatible electronic keyers, I recently built a PK-4 SSR keyer ($23) from Jackson Harbor Press: http://jacksonharbor.home.att.net/pk4ssr.htm The postage stamp board can key rigs with up to 400v on the keyline. I built mine in an Altoids tin and it works great with my Drake transmitters. Previously I had wired up a relay to an electronic keyer. The PK-4 SSR is a much more optimum solution. I have no affiliation with Jackson Harbor Press, or course, I'm just a satisfied customer. Tom N7TM -- 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] Radio advice?
A TR-4 is better for CW than a TR-3 because of auto-break-in. In other words, when you put a TR-4 in CW mode, you can still hear the receiver. When you key the transmitter, a relay closes and at the end of keying, depending upon delay, the transceiver switches back into receive mode. When you put a TR-3 into CW mode, the transceiver switches to transmit mode and you no longer hear the receiver. In other words, you have to manually switch the TR-3 out of CW between transmissions. On the other hand, a TR-3 uses three 12JB6’s, which are generally less expensive than the 6JB6’s a TR-4 uses. Neither a TR-3 nor a TR-4 has any special CW filters or RIT capabilities. Later models of the TR-4C added some of these CW features. Both the TR-3 and TR-4 work well on SSB. Tom n7tm From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Tuesday, November 01, 2005 4:29 PM To: drakelist@zerobeat.net Cc: [EMAIL PROTECTED] Subject: [drakelist] Radio advice? A good friend of mine (not presently on the LIST) is interested in acquiring his first Drake rig and was interested in either the TR-3 or TR-4. I told him in many cases you can tell the quality of the radio by the lack of complaints and by the lack of mods available. As you can see my information is limited. He would appreciate if those with some insight would contact him directly: Larry W8GTT Redmond, WA [EMAIL PROTECTED] Thanks Alan KB7MBI
RE: [drakelist] Vox Rly connector
I followed Garey’s suggestion on his website for the pins and from his email, realize the brass tubing is 3/32”, not 3/16” Tom From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Tom Taylor (MSTV) Sent: Monday, October 24, 2005 2:08 PM To: George Bennett; drakelist@www.zerobeat.net Subject: RE: [drakelist] Vox Rly connector Just last week I made a cable with two homemade vox plugs on either end to connect an AC-4 to an L-4B. The plugs fit and work perfectly. Here are the steps I used: 1- buy 3/16” brass tubing from a hobby store 2- cut ¾” sections of the tube with a Dremel chucked with a cut-off wheel 3- sand one end of the pins slightly rounded 4- solder a wire into the other end of each pin 5- cut a piece of plexiglass to 3/8” x ¾” 6- drill two 3/16” holes in the plexiglass spaced the correct distance apart 7- insert the two pins into the holes – the rounded ends of the pins should stick out about a half inch 8- tape a 2.5” strip of electrical tape around the perimeter of the plexiglass base – the wires will be sticking out 9- clamp the base in a vice and pour 5 minute epoxy into the area contained by the electrical tape 10- wait for epoxy to dry 11- remove electrical tape 12- enjoy! Tom N7TM From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of George Bennett Sent: Monday, October 24, 2005 11:47 AM To: drakelist@www.zerobeat.net Subject: [drakelist] Vox Rly connector I am trying to locate the 2 pin plug that fits the vox relay jack on the back of the AC-4. Can anyone help me? Also, which side is ground? Thanks, George
RE: [drakelist] Vox Rly connector
Just last week I made a cable with two homemade vox plugs on either end to connect an AC-4 to an L-4B. The plugs fit and work perfectly. Here are the steps I used: 1- buy 3/16” brass tubing from a hobby store 2- cut ¾” sections of the tube with a Dremel chucked with a cut-off wheel 3- sand one end of the pins slightly rounded 4- solder a wire into the other end of each pin 5- cut a piece of plexiglass to 3/8” x ¾” 6- drill two 3/16” holes in the plexiglass spaced the correct distance apart 7- insert the two pins into the holes – the rounded ends of the pins should stick out about a half inch 8- tape a 2.5” strip of electrical tape around the perimeter of the plexiglass base – the wires will be sticking out 9- clamp the base in a vice and pour 5 minute epoxy into the area contained by the electrical tape 10- wait for epoxy to dry 11- remove electrical tape 12- enjoy! Tom N7TM From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of George Bennett Sent: Monday, October 24, 2005 11:47 AM To: drakelist@www.zerobeat.net Subject: [drakelist] Vox Rly connector I am trying to locate the 2 pin plug that fits the vox relay jack on the back of the AC-4. Can anyone help me? Also, which side is ground? Thanks, George
RE: [drakelist] L-4B fan noise
"Tom Taylor \(MSTV\)" <[EMAIL PROTECTED]> made an utterance to the drakelist gang -- Thanks to all who responded with the tip about the L-4B's fan's oil ports. A couple drops of oil in each port immediately solved the noise problem. The L-4B has rejoined the silent ranks. I put it on the air tonight. Man, it heats up my small office quickly. I'm surprised at the tremendous step in plate voltage between the CW and SSB settings. Thanks, Tom N7TM -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Tom Taylor (MSTV) Sent: Tuesday, October 18, 2005 11:11 AM To: drake Subject: [drakelist] L-4B fan noise "Tom Taylor \(MSTV\)" <[EMAIL PROTECTED]> made an utterance to the drakelist gang -- Drake Aficionados, I'm putting a recently purchased L-4B back on the air after the amp has experienced an unknown period of inactivity. When I powered up the L-4B last night for the first time, I noticed a rather loud hum coming from the L-4B amp deck. I reached around the back of the unit and stopped the squirrel cage fan with my fingers and the noise stopped. From reading reviews, the L-4B has earned a reputation as being relatively quiet. Has anyone else experienced a loud hum from their L-4B fan? Have you cured it? Can the L-4B's fan motor be lubricated? Curious, Tom N7TM p.s. I made the unobtanium VOX/relay plugs for the amp and ac4 using a suggestion on Garey Barrell's web site. I used 3/16" brass tube for the pins, small rectangles of plexiglass with drilled holes to hold the pins, and epoxy to seal the wires and the back ends of the plugs. -- 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 --
[drakelist] L-4B fan noise
"Tom Taylor \(MSTV\)" <[EMAIL PROTECTED]> made an utterance to the drakelist gang -- Drake Aficionados, I'm putting a recently purchased L-4B back on the air after the amp has experienced an unknown period of inactivity. When I powered up the L-4B last night for the first time, I noticed a rather loud hum coming from the L-4B amp deck. I reached around the back of the unit and stopped the squirrel cage fan with my fingers and the noise stopped. From reading reviews, the L-4B has earned a reputation as being relatively quiet. Has anyone else experienced a loud hum from their L-4B fan? Have you cured it? Can the L-4B's fan motor be lubricated? Curious, Tom N7TM p.s. I made the unobtanium VOX/relay plugs for the amp and ac4 using a suggestion on Garey Barrell's web site. I used 3/16" brass tube for the pins, small rectangles of plexiglass with drilled holes to hold the pins, and epoxy to seal the wires and the back ends of the plugs. -- 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-R relay
"Tom Taylor \(MSTV\)" <[EMAIL PROTECTED]> made an utterance to the drakelist gang -- An intermittent problem I see with my R-4 & T-4 (the xmtr without a VFO) pair is after transmitting, the receiver is often practically deaf. A few clicks of the key or mike switch to trigger the relay often fixes the problem. My theory is that the contacts on the relay, particularly the antenna switchover contact, needs cleaning. Perhaps replacing the relay with this recommended replacement will solve the problem. Tom N7TM -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Garey Barrell Sent: Wednesday, September 28, 2005 8:29 PM To: DW Harms Cc: drakelist@www.zerobeat.net Subject: Re: [drakelist] T-R relay Garey Barrell <[EMAIL PROTECTED]> made an utterance to the drakelist gang -- Dick - Why are you wasting time with EBay? You can buy a new relay, Potter & Brumfield R10-E1Y4-V2.5K, which is the standard relay in all the T(R)-4 (any) transmitters. The original Varley relay had a 15K coil, which meant very fine wire. There was a fairly high failure rate caused by the wire breaking, possibly because of the heating and cooling cycles of the transmitter. The only change necessary to use the 2.5K ohm relay above is to add a 1.5K, 1/2W resistor in series with the coil. They're available from both Digi-Key and Mouser for about $15. They're also available from Newark, and probably their Farnell division in EU. 73, Garey - K4OAH Atlanta Drake C-Line Service Manual <http://www.k4oah.com> DW Harms wrote: >"DW Harms" <[EMAIL PROTECTED]> made an utterance to the drakelist gang >-- >Drakelist de PA2DW, > >I was outbidded on E-bay for that nice T-4C T-R relay )(&(&*!^$#!@@:( >While I was sound asleep the auction ended and although for days I was the >high bidder, I was lost in the end of course. I really start to hate that >E-bay thing... >Now my question is, whom of you is the lucky winner of that relay?! Must be >one of you out there and maybe we can come to some [EMAIL PROTECTED] ;))) > >73, Dick PA2DW > > -- 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] pricing and the TR-5
Sounds like it's time to get the Discovery Channel to sponser a diving expedition to recover those radios! (like they did with Gus Grissom's Liberty Bell) The documentary would be fantastic; at least to those of us on this list :-) Tom N7TM From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Ron BakerSent: Wednesday, July 14, 2004 4:40 PMTo: James E. Lanier; [EMAIL PROTECTED]Subject: Re: [drakelist] pricing and the TR-5 Jim, the TR5 is a fine radio and works well and was to be the solid state replacement for the TR4 series. I think the reason for the high value is its a rare item to find. Drake only manufactured 517 units, as compared to around 3000 or more TR7's. Of those 517 TR5's built we believe a large number of them (estimated around 200 units) were lost as sea while being shipped to South America. 73, Ron / WB4HFN - Original Message - From: James E. Lanier To: [EMAIL PROTECTED] Sent: Wednesday, July 14, 2004 6:32 PM Subject: [drakelist] pricing and the TR-5 I checked out the link http://www.wb4hfn.com/DrakePricing.htm and was please to see that my rig (TR-5) is apparently valuable. It seems to be as valuable as the tr-7 . To what do you attribute this? Jim N4BPM www.chemroc.com
