[Drakelist] test
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Re: [Drakelist] R-4A PTO Woes
Regarding the PTO Can "RFI GASKET", I don't think you will gain anything from gasketing the shield. Gasketing of enclosures in the normal sense isn't going to be the same at the frequency of the PTO as it is at VHF where we commonly see it. I think the idea is not to try to trap RF but to limit the magnetics change due to any mechanical movement. A simple solid connection should suffice. In any case, even if one were to gasket the base, the hole in the back end is still there, so what would be gained? If those little spring clips are broken, replace them with a simple "L" bracket for a 4-40 machine screw. FWIW Curt ne and Edward Swynar wrote: Hi Steve, Well, you are MOST fortunate that you've located a good source of "...parts" PTOs there...! The only potential problems there would be (A) finding an exact replacement for yours (I understand that Drake, like other manufacturers, had occasion to change things "...on the fly"), and/or (B) getting a replacement PTO with the exact same woes (or worse) as yours there now...! Hi Hi. Hopefully you'll hit the proverbial home run, however, & all will be well again... In the meanwhile, Garey HAS stated, repeatedly, his desire to locate an "ailing" PTO, for dissectrion on his work/test bench...if you do happen to find a good working replacement, you may wish to keep Garey in mind as a potential benefactor for your "...excess"...! Good luck there---and do please keep everyone posted as to your progress. I've been mulling over some ideas re. an effective RFI "...gasket" here to improve the bonding between the bottom of the shield can & its mating metal surface, & seem to have settled upon the idea of a "string" of RG-59 coaxial shield braid long enough to go about the perimeter of the shield can: I'm thinking that I could then secure the braid to both surfaces---physically to the can, electrically to the base---by tightening a plastic automotive "chicken band" along the length of the braid... Stay tuned...! ~73~ de Eddy VE3CUI - VE3XZ ** - Original Message - From: "Steve Wedge" To: "Diane and Edward Swynar" Cc: ; Sent: Sunday, January 09, 2011 12:47 PM Subject: Re: [Drakelist] R-4A PTO Woes Thanks for all the good info, Eddy, and I did somewhat remember seeing some of your travails being posted on the board here. It does seem that the culprit is likely to be the cover, as I can make it change frequency by wiggling it. After again examining the knob per Garrey's suggestion, I feel that it is tighter than the one on the perfectly-working PTO on my T-4X Very little axial play (but there is some and it affects frequency). It looks like I'll have to see if there's any way for me to tighten those cover spring clips. I'm still curious about the raspiness, however. I won't mess with it long in the radio - I think I've located a source of a couple of PTO's that were pulled from parts rigs, so that may be the easier (wimpy) way out. I'll keep the list up to date. 73, Steve Wedge, W1ES/4 To be is to do - Socrates To do is to be - Plato Do be do be do. - Sinatra All my computers have my signature with various pearls of wisdom appended thereto. -- From: "Diane and Edward Swynar" Sent: Sunday, January 09, 2011 8:55 AM To: "Steve Wedge" Cc: ; Subject: Re: [Drakelist] R-4A PTO Woes Hi Steve, Of course, take heed to initially eliminate "...the usual suspects" just as Garey suggests in finding the cause of your receiver PTO's raspiness & instability...but sooner or later, you just *may* have to bite the proverbial bullet & get inside of that PTO shield can to see exactly "...what's what" therein... Now, if anyone on the Reflector starting to read this has no issue(s) whatsoever with the PTO(s) in their rigs, consider yourself blessed!---and feel free to delete this mesage before proceeding any further (it IS rather long). My experiences with the PTO of my T-4X are pretty much well-documented in previous posts...but to summarize briefly, the signal from my transmitter PTO would intermittently become raspy and off-frequency, as well. After bravely(!) removing the PTO cover---and the entire PTO circuit board itself!---I first cleaned everything that I could see with isopropyl rubbing alcohol...no change. I then replaced the zener diode therein...no change. I next added the Drake-prescribed after-market grounding strap inside the PTO...no change. Finally, I did a visual inspection of the solder traces on the board of the PTO, & discovered that one of the joints of the 3000-pfd. silver mica capacitor there appeared to be "crystalized" (as in "cold") under a magnifying glass. I ultimately removed this capacitor outright, & replaced it with a pair of 1500-pfd. s.m.'s in parallel. Did that solve the issue...? YES, and NO. As long
Re: [Drakelist] R-4A PTO Woes
Struck out with my source, so it looks like I'll be tearing this thing out eventually. For now, I use the PTO in the transmitter and everything sounds and works great. Yeah, I'm going to have to look up what the differences are - I.e., can I use a PTO from a TR-4, R-4 or R-4B? I know they changed over to an FET design at some point, but believe the frequency is identical. Steve Wedge, W1ES/4 To be is to do - Socrates To do is to be - Plato Do be do be do. - Sinatra All my computers have my signature with various pearls of wisdom appended thereto. -- From: "Diane and Edward Swynar" Sent: Sunday, January 09, 2011 6:03 PM To: "Steve Wedge" Cc: ; Subject: Re: [Drakelist] R-4A PTO Woes Hi Steve, Well, you are MOST fortunate that you've located a good source of "...parts" PTOs there...! The only potential problems there would be (A) finding an exact replacement for yours (I understand that Drake, like other manufacturers, had occasion to change things "...on the fly"), and/or (B) getting a replacement PTO with the exact same woes (or worse) as yours there now...! Hi Hi. Hopefully you'll hit the proverbial home run, however, & all will be well again... In the meanwhile, Garey HAS stated, repeatedly, his desire to locate an "ailing" PTO, for dissectrion on his work/test bench...if you do happen to find a good working replacement, you may wish to keep Garey in mind as a potential benefactor for your "...excess"...! Good luck there---and do please keep everyone posted as to your progress. I've been mulling over some ideas re. an effective RFI "...gasket" here to improve the bonding between the bottom of the shield can & its mating metal surface, & seem to have settled upon the idea of a "string" of RG-59 coaxial shield braid long enough to go about the perimeter of the shield can: I'm thinking that I could then secure the braid to both surfaces---physically to the can, electrically to the base---by tightening a plastic automotive "chicken band" along the length of the braid... Stay tuned...! ~73~ de Eddy VE3CUI - VE3XZ ** - Original Message - From: "Steve Wedge" To: "Diane and Edward Swynar" Cc: ; Sent: Sunday, January 09, 2011 12:47 PM Subject: Re: [Drakelist] R-4A PTO Woes Thanks for all the good info, Eddy, and I did somewhat remember seeing some of your travails being posted on the board here. It does seem that the culprit is likely to be the cover, as I can make it change frequency by wiggling it. After again examining the knob per Garrey's suggestion, I feel that it is tighter than the one on the perfectly-working PTO on my T-4X Very little axial play (but there is some and it affects frequency). It looks like I'll have to see if there's any way for me to tighten those cover spring clips. I'm still curious about the raspiness, however. I won't mess with it long in the radio - I think I've located a source of a couple of PTO's that were pulled from parts rigs, so that may be the easier (wimpy) way out. I'll keep the list up to date. 73, Steve Wedge, W1ES/4 To be is to do - Socrates To do is to be - Plato Do be do be do. - Sinatra All my computers have my signature with various pearls of wisdom appended thereto. -- From: "Diane and Edward Swynar" Sent: Sunday, January 09, 2011 8:55 AM To: "Steve Wedge" Cc: ; Subject: Re: [Drakelist] R-4A PTO Woes > Hi Steve, > > Of course, take heed to initially eliminate "...the usual suspects" > just > as > Garey suggests in finding the cause of your receiver PTO's raspiness & > instability...but sooner or later, you just *may* have to bite the > proverbial bullet & get inside of that PTO shield can to see exactly > "...what's what" therein... > > Now, if anyone on the Reflector starting to read this has no issue(s) > whatsoever with the PTO(s) in their rigs, consider yourself blessed!---and > feel free to delete this mesage before proceeding any further (it IS > rather > long). > > My experiences with the PTO of my T-4X are pretty much well-documented in > previous posts...but to summarize briefly, the signal from my transmitter > PTO would intermittently become raspy and off-frequency, as well. After > bravely(!) removing the PTO cover---and the entire PTO circuit board > itself!---I first cleaned everything that I could see with isopropyl > rubbing > alcohol...no change. > > I then replaced the zener diode therein...no change. > > I next added the Drake-prescribed after-market grounding strap inside the > PTO...no change. > > Finally, I did a visual inspection of the solder traces on the board of > the > PTO, & discovered that one of the joints of the 3000-pfd. silver mica > capacitor there appeared to be "crystalized" (as in "cold") under a > magnifying glass. I ultimately removed this capacitor outright, & replaced > it with a pair of 1500-pfd.
[Drakelist] FS: Variety of Radio Items
FOR SALE - Various Radio Items: Hallicrafters Sky Buddy S19, Excellent - $165.00 Yaesu FT-101E, may need some work - $225.00 KLM ECHO 70 SSB-CW Transceiver for UHF 70cm Band - $95.00 RL Drake Company receiver 100 kHz - 30.0 MHz PRN1000 - $145.00 Two 250 watt variacs - Each designed for 0 - 250 V AC at 1 amp. Can be used at 120V AC also. Available for $27.00 each Heath HD-15 Phone Patch - cherry, $15.00 Panel meter - 0 to 200 mA DC, 2" diameter with hardware - $5.00 Group of variable capacitors - Consists of TWO DUAL 500pf air variable capacitors and TWO 350 pF single air variable capacitors. ALL FOUR for a total of $20.00 plus shipping. MFJ-760 notch filter - 80 to 180 MHz... $4.00 Hamtronics 800 MHz receiving converter $4.00 14V DC at 4.5 Amps power supply. AC operated supply. Based on a circuit Board. Rugged design - great for filaments or for use with other projects. Excellent working condition. QTY 1 available for $8.00 plus shipping. More parts and accessory items will be added soon... 73 - Brian, AF4K Pictures and details here: http://www.af4k.com/radios.htm http://www.af4k.com/miscpart.htm ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] R-4A PTO Woes
Hi Steve, Well, you are MOST fortunate that you've located a good source of "...parts" PTOs there...! The only potential problems there would be (A) finding an exact replacement for yours (I understand that Drake, like other manufacturers, had occasion to change things "...on the fly"), and/or (B) getting a replacement PTO with the exact same woes (or worse) as yours there now...! Hi Hi. Hopefully you'll hit the proverbial home run, however, & all will be well again... In the meanwhile, Garey HAS stated, repeatedly, his desire to locate an "ailing" PTO, for dissectrion on his work/test bench...if you do happen to find a good working replacement, you may wish to keep Garey in mind as a potential benefactor for your "...excess"...! Good luck there---and do please keep everyone posted as to your progress. I've been mulling over some ideas re. an effective RFI "...gasket" here to improve the bonding between the bottom of the shield can & its mating metal surface, & seem to have settled upon the idea of a "string" of RG-59 coaxial shield braid long enough to go about the perimeter of the shield can: I'm thinking that I could then secure the braid to both surfaces---physically to the can, electrically to the base---by tightening a plastic automotive "chicken band" along the length of the braid... Stay tuned...! ~73~ de Eddy VE3CUI - VE3XZ ** - Original Message - From: "Steve Wedge" To: "Diane and Edward Swynar" Cc: ; Sent: Sunday, January 09, 2011 12:47 PM Subject: Re: [Drakelist] R-4A PTO Woes > Thanks for all the good info, Eddy, and I did somewhat remember seeing some > of your travails being posted on the board here. > > It does seem that the culprit is likely to be the cover, as I can make it > change frequency by wiggling it. After again examining the knob per > Garrey's suggestion, I feel that it is tighter than the one on the > perfectly-working PTO on my T-4X Very little axial play (but there is some > and it affects frequency). > > It looks like I'll have to see if there's any way for me to tighten those > cover spring clips. I'm still curious about the raspiness, however. > > I won't mess with it long in the radio - I think I've located a source of a > couple of PTO's that were pulled from parts rigs, so that may be the easier > (wimpy) way out. > > I'll keep the list up to date. > > 73, > > Steve Wedge, W1ES/4 > > To be is to do - Socrates > To do is to be - Plato > Do be do be do. - Sinatra > > All my computers have my signature with various pearls of wisdom appended > thereto. > > > -- > From: "Diane and Edward Swynar" > Sent: Sunday, January 09, 2011 8:55 AM > To: "Steve Wedge" > Cc: ; > Subject: Re: [Drakelist] R-4A PTO Woes > > > Hi Steve, > > > > Of course, take heed to initially eliminate "...the usual suspects" just > > as > > Garey suggests in finding the cause of your receiver PTO's raspiness & > > instability...but sooner or later, you just *may* have to bite the > > proverbial bullet & get inside of that PTO shield can to see exactly > > "...what's what" therein... > > > > Now, if anyone on the Reflector starting to read this has no issue(s) > > whatsoever with the PTO(s) in their rigs, consider yourself blessed!---and > > feel free to delete this mesage before proceeding any further (it IS > > rather > > long). > > > > My experiences with the PTO of my T-4X are pretty much well-documented in > > previous posts...but to summarize briefly, the signal from my transmitter > > PTO would intermittently become raspy and off-frequency, as well. After > > bravely(!) removing the PTO cover---and the entire PTO circuit board > > itself!---I first cleaned everything that I could see with isopropyl > > rubbing > > alcohol...no change. > > > > I then replaced the zener diode therein...no change. > > > > I next added the Drake-prescribed after-market grounding strap inside the > > PTO...no change. > > > > Finally, I did a visual inspection of the solder traces on the board of > > the > > PTO, & discovered that one of the joints of the 3000-pfd. silver mica > > capacitor there appeared to be "crystalized" (as in "cold") under a > > magnifying glass. I ultimately removed this capacitor outright, & replaced > > it with a pair of 1500-pfd. s.m.'s in parallel. > > > > Did that solve the issue...? YES, and NO. As long as the rig is allowed to > > thoroughly warm-up for about 1 to 2 hours, all seems well and > > good---however, even after this "heat soak", there continue to be very > > infrequent (but still there!) minor frequency "creeps" up in frequency > > that > > I can detect, of a few tenths of hertz (but no raspiness). > > > > Now, I should point out that my Drake Twins are located in my basement, > > where the average ambient room temperature hovers at 50F (+/-)---and I > > cool > > the 6JB6A finals of the T-4X by fanning air OUT of the enclosure. My > > suspicion initially at this po
Re: [Drakelist] R-4A PTO Woes
Thanks for all the good info, Eddy, and I did somewhat remember seeing some of your travails being posted on the board here. It does seem that the culprit is likely to be the cover, as I can make it change frequency by wiggling it. After again examining the knob per Garrey's suggestion, I feel that it is tighter than the one on the perfectly-working PTO on my T-4X Very little axial play (but there is some and it affects frequency). It looks like I'll have to see if there's any way for me to tighten those cover spring clips. I'm still curious about the raspiness, however. I won't mess with it long in the radio - I think I've located a source of a couple of PTO's that were pulled from parts rigs, so that may be the easier (wimpy) way out. I'll keep the list up to date. 73, Steve Wedge, W1ES/4 To be is to do - Socrates To do is to be - Plato Do be do be do. - Sinatra All my computers have my signature with various pearls of wisdom appended thereto. -- From: "Diane and Edward Swynar" Sent: Sunday, January 09, 2011 8:55 AM To: "Steve Wedge" Cc: ; Subject: Re: [Drakelist] R-4A PTO Woes Hi Steve, Of course, take heed to initially eliminate "...the usual suspects" just as Garey suggests in finding the cause of your receiver PTO's raspiness & instability...but sooner or later, you just *may* have to bite the proverbial bullet & get inside of that PTO shield can to see exactly "...what's what" therein... Now, if anyone on the Reflector starting to read this has no issue(s) whatsoever with the PTO(s) in their rigs, consider yourself blessed!---and feel free to delete this mesage before proceeding any further (it IS rather long). My experiences with the PTO of my T-4X are pretty much well-documented in previous posts...but to summarize briefly, the signal from my transmitter PTO would intermittently become raspy and off-frequency, as well. After bravely(!) removing the PTO cover---and the entire PTO circuit board itself!---I first cleaned everything that I could see with isopropyl rubbing alcohol...no change. I then replaced the zener diode therein...no change. I next added the Drake-prescribed after-market grounding strap inside the PTO...no change. Finally, I did a visual inspection of the solder traces on the board of the PTO, & discovered that one of the joints of the 3000-pfd. silver mica capacitor there appeared to be "crystalized" (as in "cold") under a magnifying glass. I ultimately removed this capacitor outright, & replaced it with a pair of 1500-pfd. s.m.'s in parallel. Did that solve the issue...? YES, and NO. As long as the rig is allowed to thoroughly warm-up for about 1 to 2 hours, all seems well and good---however, even after this "heat soak", there continue to be very infrequent (but still there!) minor frequency "creeps" up in frequency that I can detect, of a few tenths of hertz (but no raspiness). Now, I should point out that my Drake Twins are located in my basement, where the average ambient room temperature hovers at 50F (+/-)---and I cool the 6JB6A finals of the T-4X by fanning air OUT of the enclosure. My suspicion initially at this point was that any of the temperature compensating capacitors (themselves almost a half century old now!) inside that PTO shield never really have much of a chance to really & truly warm-up, as such, and were acting "flakey" in getting up to speed---hence the continued display of off & on drift. And so I pondered the possibility of installing a small 12-volt pilot lamp "heater" inside the can, to speed things up to a constant level of warmth... This past week I proceeded to look into that notion, and started by removing the PTO cover. HELLO!!! the locking tabs on one side were NOT FULLY SECURED into the mounting holes! As well, I concluded that ANY "heater bulb" entry into the tight quarters of PTO shield would necessitate that wires be in close proximity to the coil field---and I had no idea what the consequences that might have upon the dial calibration...and I really did NOT want to find out, either! So I simply replaced the can/cover, being extra careful this time that the locking tabs were engaged. Now, fast forward to yesterday, when I stumbled upon this nugget in the matter of ferrite-rod oscillator tank coils (as in Drake PTOs), which I quote now from page 85 of Harry D. Hooton's (W6TYH) 1968 book entitled, "SINGLE SIDE-BAND: THEORY AND PRACTICE"... To whit: "IN ORDER TO MAINTAIN ITS HIGH-Q THE FERRITE-ROD COIL SHOULD BE KEPT AWAY FROM THE METAL SHIELDING, BECAUSE IT IS QUITE SENSITIVE TO ANY EXPANSION IN THE SHIELDING DUE TO HEAT. THE SHIELD BOX SHOULD BE CONSTRUCTED OF FAIRLY HEAVY-GAUGE ALUMINUM. UNLESS THE BOX SEAMS AND THE TOP AND BOTTOM PLATES MAINTAIN A GOOD ELECTRICAL CONNECTION DURING EXPANSION OF THE METAL, THE COIL FIELD WILL BE DISTURBED AND CAUSE THE OSCILLATOR FREQUENCY SUDDENLY TO INCREASE FROM TIME TO TIME." Hmmm... If it takes
Re: [Drakelist] R-4A PTO Woes
Hi Steve, Of course, take heed to initially eliminate "...the usual suspects" just as Garey suggests in finding the cause of your receiver PTO's raspiness & instability...but sooner or later, you just *may* have to bite the proverbial bullet & get inside of that PTO shield can to see exactly "...what's what" therein... Now, if anyone on the Reflector starting to read this has no issue(s) whatsoever with the PTO(s) in their rigs, consider yourself blessed!---and feel free to delete this mesage before proceeding any further (it IS rather long). My experiences with the PTO of my T-4X are pretty much well-documented in previous posts...but to summarize briefly, the signal from my transmitter PTO would intermittently become raspy and off-frequency, as well. After bravely(!) removing the PTO cover---and the entire PTO circuit board itself!---I first cleaned everything that I could see with isopropyl rubbing alcohol...no change. I then replaced the zener diode therein...no change. I next added the Drake-prescribed after-market grounding strap inside the PTO...no change. Finally, I did a visual inspection of the solder traces on the board of the PTO, & discovered that one of the joints of the 3000-pfd. silver mica capacitor there appeared to be "crystalized" (as in "cold") under a magnifying glass. I ultimately removed this capacitor outright, & replaced it with a pair of 1500-pfd. s.m.'s in parallel. Did that solve the issue...? YES, and NO. As long as the rig is allowed to thoroughly warm-up for about 1 to 2 hours, all seems well and good---however, even after this "heat soak", there continue to be very infrequent (but still there!) minor frequency "creeps" up in frequency that I can detect, of a few tenths of hertz (but no raspiness). Now, I should point out that my Drake Twins are located in my basement, where the average ambient room temperature hovers at 50F (+/-)---and I cool the 6JB6A finals of the T-4X by fanning air OUT of the enclosure. My suspicion initially at this point was that any of the temperature compensating capacitors (themselves almost a half century old now!) inside that PTO shield never really have much of a chance to really & truly warm-up, as such, and were acting "flakey" in getting up to speed---hence the continued display of off & on drift. And so I pondered the possibility of installing a small 12-volt pilot lamp "heater" inside the can, to speed things up to a constant level of warmth... This past week I proceeded to look into that notion, and started by removing the PTO cover. HELLO!!! the locking tabs on one side were NOT FULLY SECURED into the mounting holes! As well, I concluded that ANY "heater bulb" entry into the tight quarters of PTO shield would necessitate that wires be in close proximity to the coil field---and I had no idea what the consequences that might have upon the dial calibration...and I really did NOT want to find out, either! So I simply replaced the can/cover, being extra careful this time that the locking tabs were engaged. Now, fast forward to yesterday, when I stumbled upon this nugget in the matter of ferrite-rod oscillator tank coils (as in Drake PTOs), which I quote now from page 85 of Harry D. Hooton's (W6TYH) 1968 book entitled, "SINGLE SIDE-BAND: THEORY AND PRACTICE"... To whit: "IN ORDER TO MAINTAIN ITS HIGH-Q THE FERRITE-ROD COIL SHOULD BE KEPT AWAY FROM THE METAL SHIELDING, BECAUSE IT IS QUITE SENSITIVE TO ANY EXPANSION IN THE SHIELDING DUE TO HEAT. THE SHIELD BOX SHOULD BE CONSTRUCTED OF FAIRLY HEAVY-GAUGE ALUMINUM. UNLESS THE BOX SEAMS AND THE TOP AND BOTTOM PLATES MAINTAIN A GOOD ELECTRICAL CONNECTION DURING EXPANSION OF THE METAL, THE COIL FIELD WILL BE DISTURBED AND CAUSE THE OSCILLATOR FREQUENCY SUDDENLY TO INCREASE FROM TIME TO TIME." Hmmm... If it takes that little to adversely affect oscillator frequency, the detrimental effect upon stability of one of the "ears" of one of the locking tabs being loose now makes sense to me---just as the fact that continual removal & replacement of the can probably has a bearing upon shielding integrity, that heretofore was not compromised in any way since the rig left Miamisburg in 1966! I'm next going to try some sort of "RFI gasketing" scheme at the base of the PTO shield can, to ensure that there are no "cracks" in the shielding that could be affected by normal heating of the rig... Steve, hopefully your problem might be traced to a simple need for a clean-up of dried-up grease/dirt in the PTO mechanism. While my own personal "...journey of discovery" here with my PTO has been enlightening, I wouldn't particularly wish the trip I've been taking upon anyone else...! Hi Hi ~73~ de Eddy VE3CUI - VE3XZ * - Original Message - From: "Steve Wedge" To: "Diane and Edward Swynar" Sent: Saturday, January 08, 2011 8:37 PM Subject: Re: [Drakelist] R-4A PTO Woes > I tried to take it off when I cleaned the receiver, Eddy. Those > spring-loaded
[Drakelist] TR7 Drift - Many Thanks!
Hello All! The suggestions you guys have made in response to my request for a TR7 drift remedy are very much appreciated. I've read just about everything you've referred me to and now I'm much better informed about making a decision. Thanks very, very much!!! VY 73, Tony K4KYO ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
