Three monitors is.. Awesome I can only agree on that as "It systems specialist" == Keyboard basher..
Funny you bring up Mr. Carlson, was checking my mail on the phone and saw the first line in your reply... and was going to write to you that, the "sound" i noticed was precisely what Mr.Carlson was tracing with he's "Super probe" doohickey thingy thing..
I have seriously considered he's probe, I do have the documentation, but never got around to build one, that is that I never had the need.. Until now. Maybe when the day is 35 hours and not 24 hours.. One never knows..
/Michael - oz8abr
On Sat, Mar 9, 2024 at 9:05?PM Steve Wedge, W1ES/4 via <w1es= [email protected]> wrote: Crackling sounds that affect the AGC (and thus cause the meter to deflect) are worthy of investigation.? You may have a component that is either cracking (resistor) or has some intermittent dialectric issues (capacitor).
I have been promising myself that I would look into creating one of those "Mr. Carlson Super Probes".? "Mr. Carlson's Lab" is on YouTube and he created an AC probe that can sniff out problems like internally arcing components.? The probe is similar in concept to the old signal tracers but it is much more sensitive.? I believe he has two versions: one with through-hole and the other using SMT.? He demonstrated the probe on an old receiver that was showing "crackling" noises. and was able to find the bad cap within a few minutes.
Anyway, I scored another victory today: I figured out how to add a 3rd monitor to the shack computer!? More screen area -- yay!
73,
Steve Wedge, W1ES/4
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
On Saturday, March 9th, 2024 at 1:14 PM, Michael Jensen < kavigal@...> wrote:
Well sorry for the slow reply, work just tend to take up too much of one's spare time ;). Sounds like a very nice trip you and XYL is planning, now I do not travel much these days(I used to), now I just mainly work from home and enjoy monitoring the HF bands, when 'Teams' decides to leave me alone ;).
About that Beer.. Guess I already owe you one, at least as an excuse to get myself one.
Been a few years since I was in Copenhagen, I live in the opposite end of the country all the way up to the North about 50KM south of the most northern point..
And yes we will get to the bottom of this issue, actually I notice something, when I turn on the radio 'ON' to "standby" position the meters consequential "jumps" from ~S9+20 to the S9+40 meter mark, first time I noticed I just though "ohh meter is sticky" but then while troubleshooting I fiddled with the RF gain and guess what? No "sticky" meter when RF gain is fully cranked up quickly.
I noticed twice when "cold" starting the rig, and coinciding "crackling" sound when the meter "jumped", not sure what the right term is in English / U.S.A'ish but same sound a hot 6146B tube can produce just not so pronounced.
It may not be related, just noticed it.. So.. status quo, really eager to get that 12be6 swapped, but the mail man is apparently on vacation in Hawaii current time.
/Michael.
On Thu, Mar 7, 2024 at 6:48?PM Steve Wedge, W1ES/4 via <w1es= [email protected]> wrote: Yeah, that's a shame that we still have such impediments. In the grand scheme of things, a few 60 year old tubes are nothing. If I was going to Demark this year, I'd pop a couple in my bag and trade them for a beer but we will not be in the area. We will be in HB9, DL, OE, OK, F, G, GW, GM and TF this summer. My XYL is not a ham, so I'm not bringing any radios, unfortunately :-) I mention this in case you're in any of these areas in June or July.
In a couple years, perhaps, we will get to Scandinavia. I worked in Copenhagen for a week long ago and have wanted to tour that area.
We will get to the bottom of this.
73,
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent with secure email.
On Thursday, March 7th, 2024 at 12:26 PM, Michael Jensen < kavigal@...> wrote:
Steve, I'd love the approach of shotgunning, but nope I do not have a complete set.
I do have 2x12ba6 in the mail and 1 12be6 also in the mail, so that will be the starting point.
I did consider and I'd love to get a complete set from K5SVC, but it would add more than 4 times
the money I have in the R4B already, getting tubes from the US to Europe is .. insane..
So thank you to the Danish Government ;)
Anyways, will try the three tube change first, that's kinda where I'm at now.
/Michael
On Thu, Mar 7, 2024 at 5:33?PM Steve Wedge, W1ES/4 via <w1es= [email protected]> wrote: Now is the time, if you either have a spare set or have another R-4B, to swap every tube out at the same time (¡°shotgunning¡±).
I had an R-4B that was vexing me to no end until I replaced all the tubes and then put swapped the old ones back, one at a time. I found two bad/gassy 12BA6¡¯s and a 12BE6 that passed the tube tester but was no good.
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
On Thu, Mar 7, 2024 at 09:29, Michael Jensen < kavigal@...> wrote: When unpowered, S1+a hair, so very close to zero.
Have checked the following resistors so fare... Just FYI, nothing more.. R9 1.5K** Board 9 OK
R8 220K** Chassis Right Side -R OK
R12 1.5k**Board 9 OK
R13 1.5K**Board 9 OK
R16 1.5K**Board 7 OK
R17 12K* OK
R24 18K* OK
R136 1k** Chassis Left Side -R OK
R142 4.7K**Board 3 OK
R146 22K** Board 3 -- coil OK
/Michael.
On Thu, Mar 7, 2024 at 3:19?PM Steve Wedge, W1ES/4 via <w1es= [email protected]> wrote: Yes, I have been bit by one of the meter terminals. It hurts :-). This circuit is at around 150V potential.
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
On Thu, Mar 7, 2024 at 01:23, Glenn, OZ1HFT < glenn.mh.dk@...> wrote: Hi Michael
More safety: Let the Drake unlugged power plug and cable be visible to you, on your workbench, while you work on the Drake.
(Then it be much harder to get an accidently electric shock.)
--
best regards,
Glenn, OZ1HFT
|
Crackling sounds that affect the AGC (and thus cause the meter to deflect) are worthy of investigation.? You may have a component that is either cracking (resistor) or has some intermittent dialectric issues (capacitor).
I have been promising myself that I would look into creating one of those "Mr. Carlson Super Probes".? "Mr. Carlson's Lab" is on YouTube and he created an AC probe that can sniff out problems like internally arcing components.? The probe is similar in concept to the old signal tracers but it is much more sensitive.? I believe he has two versions: one with through-hole and the other using SMT.? He demonstrated the probe on an old receiver that was showing "crackling" noises. and was able to find the bad cap within a few minutes.
Anyway, I scored another victory today: I figured out how to add a 3rd monitor to the shack computer!? More screen area -- yay!
73,
Steve Wedge, W1ES/4
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
On Saturday, March 9th, 2024 at 1:14 PM, Michael Jensen <kavigal@...> wrote:
Well sorry for the slow reply, work just tend to take up too much of one's spare time ;). Sounds like a very nice trip you and XYL is planning, now I do not travel much these days(I used to), now I just mainly work from home and enjoy monitoring the HF bands, when 'Teams' decides to leave me alone ;).
About that Beer.. Guess I already owe you one, at least as an excuse to get myself one.
Been a few years since I was in Copenhagen, I live in the opposite end of the country all the way up to the North about 50KM south of the most northern point..
And yes we will get to the bottom of this issue, actually I notice something, when I turn on the radio 'ON' to "standby" position the meters consequential "jumps" from ~S9+20 to the S9+40 meter mark, first time I noticed I just though "ohh meter is sticky" but then while troubleshooting I fiddled with the RF gain and guess what? No "sticky" meter when RF gain is fully cranked up quickly.
I noticed twice when "cold" starting the rig, and coinciding "crackling" sound when the meter "jumped", not sure what the right term is in English / U.S.A'ish but same sound a hot 6146B tube can produce just not so pronounced.
It may not be related, just noticed it.. So.. status quo, really eager to get that 12be6 swapped, but the mail man is apparently on vacation in Hawaii current time.
/Michael.
On Thu, Mar 7, 2024 at 6:48?PM Steve Wedge, W1ES/4 via <w1es= [email protected]> wrote: Yeah, that's a shame that we still have such impediments. In the grand scheme of things, a few 60 year old tubes are nothing. If I was going to Demark this year, I'd pop a couple in my bag and trade them for a beer but we will not be in the area. We will be in HB9, DL, OE, OK, F, G, GW, GM and TF this summer. My XYL is not a ham, so I'm not bringing any radios, unfortunately :-) I mention this in case you're in any of these areas in June or July.
In a couple years, perhaps, we will get to Scandinavia. I worked in Copenhagen for a week long ago and have wanted to tour that area.
We will get to the bottom of this.
73,
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent with secure email.
On Thursday, March 7th, 2024 at 12:26 PM, Michael Jensen < kavigal@...> wrote:
Steve, I'd love the approach of shotgunning, but nope I do not have a complete set.
I do have 2x12ba6 in the mail and 1 12be6 also in the mail, so that will be the starting point.
I did consider and I'd love to get a complete set from K5SVC, but it would add more than 4 times
the money I have in the R4B already, getting tubes from the US to Europe is .. insane..
So thank you to the Danish Government ;)
Anyways, will try the three tube change first, that's kinda where I'm at now.
/Michael
On Thu, Mar 7, 2024 at 5:33?PM Steve Wedge, W1ES/4 via <w1es= [email protected]> wrote: Now is the time, if you either have a spare set or have another R-4B, to swap every tube out at the same time (¡°shotgunning¡±).
I had an R-4B that was vexing me to no end until I replaced all the tubes and then put swapped the old ones back, one at a time. I found two bad/gassy 12BA6¡¯s and a 12BE6 that passed the tube tester but was no good.
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
On Thu, Mar 7, 2024 at 09:29, Michael Jensen < kavigal@...> wrote: When unpowered, S1+a hair, so very close to zero.
Have checked the following resistors so fare... Just FYI, nothing more.. R9 1.5K** Board 9 OK
R8 220K** Chassis Right Side -R OK
R12 1.5k**Board 9 OK
R13 1.5K**Board 9 OK
R16 1.5K**Board 7 OK
R17 12K* OK
R24 18K* OK
R136 1k** Chassis Left Side -R OK
R142 4.7K**Board 3 OK
R146 22K** Board 3 -- coil OK
/Michael.
On Thu, Mar 7, 2024 at 3:19?PM Steve Wedge, W1ES/4 via <w1es= [email protected]> wrote: Yes, I have been bit by one of the meter terminals. It hurts :-). This circuit is at around 150V potential.
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
On Thu, Mar 7, 2024 at 01:23, Glenn, OZ1HFT < glenn.mh.dk@...> wrote: Hi Michael
More safety: Let the Drake unlugged power plug and cable be visible to you, on your workbench, while you work on the Drake.
(Then it be much harder to get an accidently electric shock.)
--
best regards,
Glenn, OZ1HFT
|
Re: Latest problem with RV-75
I just now realized that I had grabbed a 1:1 probe instead of a usual 10:1, so I will go back and look again. I suspect that Q206 or Q207 might be the culprit also will have to troubleshoot some more.? Thanks for the hint.? Work bench is crowded now with my TR7 on the blink. Blowing the 5 amp fuse. I suspect something is grounded inside and will have to take the cover off.
73? Bob
|
Re: Latest problem with RV-75
If you are not seeing 46 MHz (third harmonic of the crystal) at least 1.5v P-P at the VCXO test point after the coils are peaked you will not have proper output. I would look around Q207 and Q206. You will probably want to use a 10:1 probe with the scope. A 1:1 probe may load the circuit too much at 46 MHz. 73 -Jim NU0C On Sat, 09 Mar 2024 11:04:39 -0800 "K6OXN Bob" <bobk6oxn@...> wrote: Thanks Jim, I don't use a metal golden screwdriver on coil slugs. I already had a shaved down nylon screw stick that I use. Was able to get the cores out the bottom and replaced them back in the top. Now to get the proper adjustment.? What I don't see is that when I power up, the freq. does not come on to xx250.0 but is in the xx340.0 area. I am trying to find where I get this freq. from since all adjustments on the Dig. board are spot on. On the RF board I don't get the 46.00000 at the VCXO TP. It is a very weak signal at best. Will keep troubleshooting.
73? Bob
|
Re: Latest problem with RV-75
Thanks Jim, I don't use a metal golden screwdriver on coil slugs. I already had a shaved down nylon screw stick that I use. Was able to get the cores out the bottom and replaced them back in the top. Now to get the proper adjustment.? What I don't see is that when I power up, the freq. does not come on to xx250.0 but is in the xx340.0 area. I am trying to find where I get this freq. from since all adjustments on the Dig. board are spot on. On the RF board I don't get the 46.00000 at the VCXO TP. It is a very weak signal at best. Will keep troubleshooting.
73? Bob
|
Well sorry for the slow reply, work just tend to take up too much of one's spare time ;). Sounds like a very nice trip you and XYL is planning, now I do not travel much these days(I used to), now I just mainly work from home and enjoy monitoring the HF bands, when 'Teams' decides to leave me alone ;).
About that Beer.. Guess I already owe you one, at least as an excuse to get myself one.
Been a few years since I was in Copenhagen, I live in the opposite end of the country all the way up to the North about 50KM south of the most northern point..
And yes we will get to the bottom of this issue, actually I notice something, when I turn on the radio 'ON' to "standby" position the meters consequential "jumps" from ~S9+20 to the S9+40 meter mark, first time I noticed I just though "ohh meter is sticky" but then while troubleshooting I fiddled with the RF gain and guess what? ?No "sticky" meter when RF gain is fully cranked up quickly.
I noticed twice when "cold" starting the rig, and coinciding "crackling" sound when the meter "jumped", not sure what the right term is in English? / U.S.A'ish but same sound a hot 6146B tube can produce just not so pronounced.
It may not be related, just noticed it.. So.. status quo, really eager to get that 12be6 swapped, but the mail man is apparently on vacation in Hawaii current time. ?
/Michael.
On Thu, Mar 7, 2024 at 6:48?PM Steve Wedge, W1ES/4 via <w1es= [email protected]> wrote: Yeah, that's a shame that we still have such impediments.? In the grand scheme of things, a few 60 year old tubes are nothing.? If I was going to Demark this year, I'd pop a couple in my bag and trade them for a beer but we will not be in the area.? We will be in HB9, DL, OE, OK, F, G, GW, GM and TF this summer.? My XYL is not a ham, so I'm not bringing any radios, unfortunately :-)? I mention this in case you're in any of these areas in June or July.
In a couple years, perhaps, we will get to Scandinavia.? I worked in Copenhagen for a week long ago and have wanted to tour that area.
We will get to the bottom of this.
73,
Steve Wedge, W1ES/4
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
On Thursday, March 7th, 2024 at 12:26 PM, Michael Jensen < kavigal@...> wrote:
Steve, I'd love the approach of shotgunning, but nope I do not have a complete set.
I do have 2x12ba6 in the mail and 1 12be6 also in the mail, so that will be the starting point.
I did consider and I'd love to get a complete set from K5SVC, but it would add more than 4 times
the money I have in the R4B already, getting tubes from the US to Europe is .. insane..
So thank you to the Danish Government ;)
Anyways, will try the three tube change first, that's kinda where I'm at now.
/Michael
On Thu, Mar 7, 2024 at 5:33?PM Steve Wedge, W1ES/4 via <w1es= [email protected]> wrote: Now is the time, if you either have a spare set or have another R-4B, to swap every tube out at the same time (¡°shotgunning¡±).
I had an R-4B that was vexing me to no end until I replaced all the tubes and then put swapped the old ones back, one at a time. I found two bad/gassy 12BA6¡¯s and a 12BE6 that passed the tube tester but was no good.
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
On Thu, Mar 7, 2024 at 09:29, Michael Jensen < kavigal@...> wrote: When unpowered, S1+a hair, so very close to zero.
Have checked the following resistors so fare... Just FYI, nothing more.. R9 1.5K** Board 9 OK
R8 220K** Chassis Right Side -R OK
R12 1.5k**Board 9 OK
R13 1.5K**Board 9 OK
R16 1.5K**Board 7 OK
R17 12K* OK
R24 18K* OK
R136 1k** Chassis Left Side -R OK
R142 4.7K**Board 3 OK
R146 22K** Board 3 -- coil OK
/Michael.
On Thu, Mar 7, 2024 at 3:19?PM Steve Wedge, W1ES/4 via <w1es= [email protected]> wrote: Yes, I have been bit by one of the meter terminals. It hurts :-). This circuit is at around 150V potential.
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
On Thu, Mar 7, 2024 at 01:23, Glenn, OZ1HFT < glenn.mh.dk@...> wrote: Hi Michael
More safety: Let the Drake unlugged power plug and cable be visible to you, on your workbench, while you work on the Drake.
(Then it be much harder to get an accidently electric shock.)
--
best regards,
Glenn, OZ1HFT
|
Hmmm¡I think some critical points were missing from Art¡¯s story.? I would first want to depose the cat under oath! ? Paul, W9AC ?
toggle quoted message
Show quoted text
From: [email protected] <[email protected]> On Behalf Of Jim VE7RF
Sent: Saturday, March 9, 2024 10:27 AM
To: [email protected]
Subject: Re: [DRAKE-RADIO] Brick on Key? On Thu, Mar 7, 2024 at 11:49 PM, Rob Sherwood wrote: Any demonstrations I saw at Dayton were sending dits. ?Rob, NC0B?
Sending 50 wpm dots into a DL, is not exactly what I would call....'brick on key'.? ?But with peak reading leds, one would not know if they were using a cxr....or 50 wpm dots.? On my yaesu MK-V, it's very easy to reduce the duty cycle of a string of dots even further, by shortening the length of each dot.? The late Art Bell, W6OBB, had a late model 1.5 kw alpha ( think it was an 89 with aux fan).....and it was tuned up for 10M FM, at 1.5 kw into a flat swr.? He drives to Vegas, 75 miles away...and? in the meantime, his cat comes into the shack, and falls asleep on the footswitch.? ?Art gets home, and smoke and stink in the shack.? ?Amp was roasted.? Art phones up Alpha and tells em it ran 1.5 kw on 10m FM for 4.5 hrs. Alpha tech tells Art..... 'don't believe all the advertising hype'.?
|
On Thu, Mar 7, 2024 at 11:49 PM, Rob Sherwood wrote:
Any demonstrations I saw at Dayton were sending dits. ?Rob, NC0B?
Sending 50 wpm dots into a DL, is not exactly what I would call....'brick on key'.? ?But with peak reading leds, one would not know if they were using a cxr....or 50 wpm dots.? On my yaesu MK-V, it's very easy to reduce the duty cycle of a string of dots even further, by shortening the length of each dot.?
The late Art Bell, W6OBB, had a late model 1.5 kw alpha ( think it was an 89 with aux fan).....and it was tuned up for 10M FM, at 1.5 kw into a flat swr.? He drives to Vegas, 75 miles away...and? in the meantime, his cat comes into the shack, and falls asleep on the footswitch.? ?Art gets home, and smoke and stink in the shack.? ?Amp was roasted.? Art phones up Alpha and tells em it ran 1.5 kw on 10m FM for 4.5 hrs. Alpha tech tells Art..... 'don't believe all the advertising hype'.?
|
I found that the 2N3877 crosses to an NTE222. These are available on eBay for around US $5 each. Avoid buying from China as those will have a higher likelihood of being counterfeit. You can select the item¡¯s origin when sorting in your search.?
I currently do not remember the current rating of the meter.?
As I¡¯ve mentioned, a particularly nasty R-4B¡¯s meter and AGC problem came from 3 bad tubes. That is why I suggest swapping out all of them as a test but understand that it¡¯s hard to find these in Europe. If you have a friend with the same receiver you could try swapping.?
73,
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
On Sat, Mar 9, 2024 at 00:24, Glenn, OZ1HFT < glenn.mh.dk@...> wrote: Hi Michael
Found this info in the files section for Drake R-4C - so the component numbering "do not work" for Drake R-4B - see the R-4C schematic:
Rob Sherwood, NC0B Updated 05/23/2013, Some comments on alignment:
/g/DRAKE-RADIO/files/Sherwood_R4C%20alignment%20tips-2013.docx
Quote: "...
When all is well, the rear S-meter zero pot (R32) should be mid-scale. Both the internal S-meter pots
(zero (R33) and max scale (R36)) should be somewhere near mid-scale. If they are way off mid-scale, then you either have a bad tube or the fixed resistor in the S-meter bridge (R34) is off value. It is not unusual for this 560 ohm resistor to be fried and read way low or way high. The S-meter will never work properly if this one resistor is off value. Also it is sometimes necessary to replace the internal S-meter pots. They can become damaged if there was an overload at some time in that part of the circuit. If the S-meter zero wanders all over the place, be suspicious of bad resistors / pots in the S-meter circuit. A leaky tube can also cause the S-meter zero to wander.
I always check tubes by substitution, and I only buy new old stock tubes, preferably Sylvania. If you try a couple tubes in a given socket, and get no more gain (S-meter reading), put the original back in place. Rarely is it necessary to re-tube the whole radio.
In very rare instances the gain of the radio may die over time. I have seen a calibrator read S9 or above, and then over 30 minutes go to near S1. If the tubes have been checked out and are good, and the above mentioned S-meter bridge resistors are OK, then the most likely solution is to replace the AGC detector transistor (Q7). This is a rare 2N3877. I have them in stock should you need one. This is not a typical problem, but it does happen.
..."
--
best regards,
Glenn, OZ1HFT
|
Hi Michael Found this info in the files section for Drake R-4C - so the component numbering "do not work" for Drake R-4B - see the R-4C schematic: Rob Sherwood, NC0B Updated 05/23/2013, Some comments on alignment: /g/DRAKE-RADIO/files/Sherwood_R4C%20alignment%20tips-2013.docxQuote: "... When all is well, the rear S-meter zero pot (R32) should be mid-scale. Both the internal S-meter pots (zero (R33) and max scale (R36)) should be somewhere near mid-scale. If they are way off mid-scale, then you either have a bad tube or the fixed resistor in the S-meter bridge (R34) is off value. It is not unusual for this 560 ohm resistor to be fried and read way low or way high. The S-meter will never work properly if this one resistor is off value. Also it is sometimes necessary to replace the internal S-meter pots. They can become damaged if there was an overload at some time in that part of the circuit. If the S-meter zero wanders all over the place, be suspicious of bad resistors / pots in the S-meter circuit. A leaky tube can also cause the S-meter zero to wander. I always check tubes by substitution, and I only buy new old stock tubes, preferably Sylvania. If you try a couple tubes in a given socket, and get no more gain (S-meter reading), put the original back in place. Rarely is it necessary to re-tube the whole radio. In very rare instances the gain of the radio may die over time. I have seen a calibrator read S9 or above, and then over 30 minutes go to near S1. If the tubes have been checked out and are good, and the above mentioned S-meter bridge resistors are OK, then the most likely solution is to replace the AGC detector transistor (Q7). This is a rare 2N3877. I have them in stock should you need one. This is not a typical problem, but it does happen. ..." -- best regards, Glenn, OZ1HFT
|
Re: Latest problem with RV-75
OK, we had this discussion earlier. Sounds like someone damaged the slugs with a metal screwdriver. The slugs are symmetrical. There will be an adjustment slot on the other end. You should be able to back them out though the hole in the board underneath the coil. It may be easier if you remove the coils from the board. DO NOT use a metal screwdriver. Get some orange wood sticks from the beauty supplies section of your local variety store and carve the end to fit the slot. the stick will break before the slug does. The slugs themselves should be largely intact. You can screw them back in from the top and adjust them as normal. It should go without saying to not use a metal tool. This is a problem that can be fixed. 73 -Jim NU0C On Fri, 08 Mar 2024 18:29:02 -0800 "K6OXN Bob" <bobk6oxn@...> wrote: It appears that L211 & L212 have problems on the RF side of the board. I founds small chips of it looks like core material in them. I am unable to section 5-6.2 to even come close to what it should be. Don't have enough expertise to troubleshoot this circuit. I have a good 100mhz counter good to 1hz and a Tektronics 100mhz scope so that is taken care of. I am open to any and all suggestions. I sent an email to Roon WB4HFN to see if he is still working on them.
73? Bob
What are the values of L211 and L212?
-- 73 -Jim NU0C
|
Re: Latest problem with RV-75
It appears that L211 & L212 have problems on the RF side of the board. I founds small chips of it looks like core material in them. I am unable to section 5-6.2 to even come close to what it should be. Don't have enough expertise to troubleshoot this circuit. I have a good 100mhz counter good to 1hz and a Tektronics 100mhz scope so that is taken care of. I am open to any and all suggestions. I sent an email to Roon WB4HFN to see if he is still working on them.
73? Bob
What are the values of L211 and L212?
|
If you keep your eyes and ears open you can get lucky. Sometimes extremely so. Back in the mid 80s I traded a $150 Diawa 2m HT for my NCL-2000. Cosmetically ugly but working to spec. Yes, the guy is still a friend of mine and I still have that amp. He was also instrumental in one of my recent Alpha acquisitions. 73 -Jim NU0C On Fri, 08 Mar 2024 12:36:48 -0800 "Steve Toth via groups.io" <stoth47@...> wrote: I looked for a linear for a couple of years - I was looking for an ICOM 2KL (hard to find) with power supply.
In the course of the search I saw Drake amps with power supplies at an average price of $1200.? I came to the conclusion $1200 was reasonable for both an amp and power supply in good cosmetic and operating condition, anything under $1200 was a good deal and anything over $1200 would have to be justified by excellent condition and how bad I wanted it.
I ended up paying $1400 for a pristine amp and power supply that worked right out of the box with no problems out of CA.
Your mileage (and desires) may vary.....?
- Steve? W7SJT
"Always look for a positive solution then Improvise, Adapt, and Overcome"
- Adaptation of the U.S. Marine Corps motto
"There are no rules here!...We're trying to accomplish something!!"
- Thomas Edison
"Success is not final, failure is not fatal.? It is the courage to continue that counts."
-?Winston Churchill
?
On Friday, March 8, 2024 at 01:11:59 PM MST, K8CCA <echapm4@...> wrote:
Thanks guys, great input.? I know it's been for sale for 2 years, so I knda figured it was a bit high.? He mentioned the Schulmann Auction, but the reality is that you need to pay to ship it there, and then give them 38% commission.? I will make an offer tomorrow as I was also thinking around 1200 was a fair price, and see what?happens.?
It's supposed to have brand?new RFparts tubes and new caps.? I am unsure what else, but I rebuilt my L4B, so I assume I will recognize the insides.? Only issue is that I won't be able to plug it into 240V, so won't be able to verify the operation.??
On the 30L-1 I bought one sans tubes at Dayton a few years ago for $100 as the guy told me it didn't have any HV after he put the Young Kim capacitor board in it and was sick of messing with?it.? It was in perfect condition,?so I figured I could fix it and risked it for that cheap.? I figured that the XFMR was toast, but was surprised?to find the HV Glitch resistor?tucked in around behind the XFMR and not connected to the board.? A quick solder job and it was fine.? Had another one given to me that had a grid to plate short from chinese crap 811s and after replacing a few parts, including the XFMR that I got from the CCA list a few months ago, it's working fine as well.? Don't really need the L7, but it would be nice to have the complete 7 line, so I will try to buy it.? Let you all know Saturday night when I get back.??
Thanks again for the insight!??
On Fri, Mar 8, 2024 at 2:49?PM jerry-KF6VB <jerry@...> wrote:
On 2024-03-08 11:20, Jim Shorney wrote:
It is all relative. An Alpha 374A sold here recently at an estate sale
for $400. *** And I saw - but didn't buy - a 30L-1 at the local ham swap for $180.
? ?It was missing one tube, and the meter glass was cracked,
but otherwise in very nice cosmetic condition.? Still regret that,
although
I already have one of those :).
? ? ? ? ? ? ? ? ? ? ?- Jerry, KF6VB
-- 73 -Jim NU0C
|
Re: Drake L7 Power output
On Fri, Mar 8, 2024 at 11:31 AM, Jim Shorney wrote:
True for casual operating but when chasing rare DX every dB counts! :D
73
-Jim
NU0C
On Fri, 08 Mar 2024 11:22:13 -0800
"amfone via groups.io" <amfone20000@...> wrote:
You are quite right Jim!But, then chasing "Rare DX" running AM is not my first choice of modes!! (or even my 2nd or 3rd) ? --
73/Rick
W4XA
*Every post is created using Linux
|
You will, to a point. The PS is identical or nearly so, as are the tune and load caps, band and power switches, and many smaller parts. The layout is markedly different inside the RF deck but electrically they are very similar. 73 -Jim NU0C On Fri, 08 Mar 2024 12:11:57 -0800 "K8CCA" <echapm4@...> wrote: It's supposed to have brand new RFparts tubes and new caps. I am unsure
what else, but I rebuilt my L4B, so I assume I will recognize the insides.
|
I looked for a linear for a couple of years - I was looking for an ICOM 2KL (hard to find) with power supply.
In the course of the search I saw Drake amps with power supplies at an average price of $1200.? I came to the conclusion $1200 was reasonable for both an amp and power supply in good cosmetic and operating condition, anything under $1200 was a good deal and anything over $1200 would have to be justified by excellent condition and how bad I wanted it.
I ended up paying $1400 for a pristine amp and power supply that worked right out of the box with no problems out of CA.
Your mileage (and desires) may vary.....?
- Steve? W7SJT
"Always look for a positive solution then Improvise, Adapt, and Overcome" - Adaptation of the U.S. Marine Corps motto
"There are no rules here!...We're trying to accomplish something!!"
- Thomas Edison
"Success is not final, failure is not fatal.? It is the courage to continue that counts." -?Winston Churchill
?
On Friday, March 8, 2024 at 01:11:59 PM MST, K8CCA <echapm4@...> wrote:
Thanks guys, great input.? I know it's been for sale for 2 years, so I knda figured it was a bit high.? He mentioned the Schulmann Auction, but the reality is that you need to pay to ship it there, and then give them 38% commission.? I will make an offer tomorrow as I was also thinking around 1200 was a fair price, and see what?happens.?
It's supposed to have brand?new RFparts tubes and new caps.? I am unsure what else, but I rebuilt my L4B, so I assume I will recognize the insides.? Only issue is that I won't be able to plug it into 240V, so won't be able to verify the operation.??
On the 30L-1 I bought one sans tubes at Dayton a few years ago for $100 as the guy told me it didn't have any HV after he put the Young Kim capacitor board in it and was sick of messing with?it.? It was in perfect condition,?so I figured I could fix it and risked it for that cheap.? I figured that the XFMR was toast, but was surprised?to find the HV Glitch resistor?tucked in around behind the XFMR and not connected to the board.? A quick solder job and it was fine.? Had another one given to me that had a grid to plate short from chinese crap 811s and after replacing a few parts, including the XFMR that I got from the CCA list a few months ago, it's working fine as well.? Don't really need the L7, but it would be nice to have the complete 7 line, so I will try to buy it.? Let you all know Saturday night when I get back.??
Thanks again for the insight!??
On Fri, Mar 8, 2024 at 2:49?PM jerry-KF6VB < jerry@...> wrote: On 2024-03-08 11:20, Jim Shorney wrote:
> It is all relative. An Alpha 374A sold here recently at an estate sale
> for $400.
*** And I saw - but didn't buy - a 30L-1 at the local ham swap for $180.
? ?It was missing one tube, and the meter glass was cracked,
but otherwise in very nice cosmetic condition.? Still regret that,
although
I already have one of those :).
? ? ? ? ? ? ? ? ? ? ?- Jerry, KF6VB
|
Rick
I think you talking about an L7 for sale near me in Michigan. I saw it on Craigslist, a good while back and at a swap too. I don't know much more about it however, I have two L7's so I did not pursue it.
Good luck Tim
WB8UHZ
On Friday, March 8, 2024 at 03:11:59 PM EST, K8CCA <echapm4@...> wrote:
Thanks guys, great input.? I know it's been for sale for 2 years, so I knda figured it was a bit high.? He mentioned the Schulmann Auction, but the reality is that you need to pay to ship it there, and then give them 38% commission.? I will make an offer tomorrow as I was also thinking around 1200 was a fair price, and see what?happens.?
It's supposed to have brand?new RFparts tubes and new caps.? I am unsure what else, but I rebuilt my L4B, so I assume I will recognize the insides.? Only issue is that I won't be able to plug it into 240V, so won't be able to verify the operation.??
On the 30L-1 I bought one sans tubes at Dayton a few years ago for $100 as the guy told me it didn't have any HV after he put the Young Kim capacitor board in it and was sick of messing with?it.? It was in perfect condition,?so I figured I could fix it and risked it for that cheap.? I figured that the XFMR was toast, but was surprised?to find the HV Glitch resistor?tucked in around behind the XFMR and not connected to the board.? A quick solder job and it was fine.? Had another one given to me that had a grid to plate short from chinese crap 811s and after replacing a few parts, including the XFMR that I got from the CCA list a few months ago, it's working fine as well.? Don't really need the L7, but it would be nice to have the complete 7 line, so I will try to buy it.? Let you all know Saturday night when I get back.??
Thanks again for the insight!??
On Fri, Mar 8, 2024 at 2:49?PM jerry-KF6VB < jerry@...> wrote: On 2024-03-08 11:20, Jim Shorney wrote:
> It is all relative. An Alpha 374A sold here recently at an estate sale
> for $400.
*** And I saw - but didn't buy - a 30L-1 at the local ham swap for $180.
? ?It was missing one tube, and the meter glass was cracked,
but otherwise in very nice cosmetic condition.? Still regret that,
although
I already have one of those :).
? ? ? ? ? ? ? ? ? ? ?- Jerry, KF6VB
|
Thanks guys, great input.? I know it's been for sale for 2 years, so I knda figured it was a bit high.? He mentioned the Schulmann Auction, but the reality is that you need to pay to ship it there, and then give them 38% commission.? I will make an offer tomorrow as I was also thinking around 1200 was a fair price, and see what?happens.?
It's supposed to have brand?new RFparts tubes and new caps.? I am unsure what else, but I rebuilt my L4B, so I assume I will recognize the insides.? Only issue is that I won't be able to plug it into 240V, so won't be able to verify the operation.??
On the 30L-1 I bought one sans tubes at Dayton a few years ago for $100 as the guy told me it didn't have any HV after he put the Young Kim capacitor board in it and was sick of messing with?it.? It was in perfect condition,?so I figured I could fix it and risked it for that cheap.? I figured that the XFMR was toast, but was surprised?to find the HV Glitch resistor?tucked in around behind the XFMR and not connected to the board.? A quick solder job and it was fine.? Had another one given to me that had a grid to plate short from chinese crap 811s and after replacing a few parts, including the XFMR that I got from the CCA list a few months ago, it's working fine as well.? Don't really need the L7, but it would be nice to have the complete 7 line, so I will try to buy it.? Let you all know Saturday night when I get back.??
Thanks again for the insight!??
On Fri, Mar 8, 2024 at 2:49?PM jerry-KF6VB < jerry@...> wrote: On 2024-03-08 11:20, Jim Shorney wrote:
> It is all relative. An Alpha 374A sold here recently at an estate sale
> for $400.
*** And I saw - but didn't buy - a 30L-1 at the local ham swap for $180.
? ?It was missing one tube, and the meter glass was cracked,
but otherwise in very nice cosmetic condition.? Still regret that,
although
I already have one of those :).
? ? ? ? ? ? ? ? ? ? ?- Jerry, KF6VB
|
On 2024-03-08 11:20, Jim Shorney wrote: It is all relative. An Alpha 374A sold here recently at an estate sale
for $400. *** And I saw - but didn't buy - a 30L-1 at the local ham swap for $180. It was missing one tube, and the meter glass was cracked, but otherwise in very nice cosmetic condition. Still regret that, although I already have one of those :). - Jerry, KF6VB
|
Re: Drake L7 Power output
True for casual operating but when chasing rare DX every dB counts! :D 73 -Jim NU0C On Fri, 08 Mar 2024 11:22:13 -0800 "amfone via groups.io" <amfone20000@...> wrote: True Rick the Drake gear used carrier control output in the AM mode ( no agc when using AM ) and the amp really? thinks its looking at an SSB signal. I've done this too with? good reports. And yes on the db difference you noted, at 100watts you have to get to 200 watts to just get 3db of signal difference on the receive end and to 400 watts to get an S-Unit.
73 Tim
WB8UHZ
On Friday, March 8, 2024 at 02:12:38 PM EST, Rick W4XA <myr748@...> wrote:
On Tue, Mar 5, 2024 at 11:21 AM, amfone wrote:
//////I normally tune for about 500 watts on the meter, this is below of course the ratings for the tube noted by Drake in the manual. If I run AM phone with the amp using a modern rig I will have a carrier output of not more that 125 watts,///////73 and thanks again.?Tim?WB8UHZ???
Tim,
You mentioned running AM with the L-4B and I thought I would share my experience running AM with my? C-Line.?? I think just about everyone here know that Drake used screen modulation with carrier control in the TR-3/4/6 transceivers and the T-4x A/B and maybe others.
It's interesting how really inefficient it is (using Drake tube transceivers and transmitters)? considering (IIRC) that they either screen modulated the driver (12BY7... TR-4/T-4X) or the final 12JB6's in the TR-3 etc.
So using an L-4B (or L-7) driving with a T-4X or TR-4 you could conceivably be running a screen modulated AM signal through 2 linear amplifiers (2 or 3 6JB6)? or just the 12JB6's in the TR-3
But it would appear that Drake intended the L-4/L-4B on AM to be operated using a Drake "driver" which would loosely approximate the average and peak power of driving with SSB.
And so I have actually used my T-4XB (that I bought new) to drive the L-4B on AM. (In the SSB MODE)
All tuned up, the "resting" carrier (controlled)? level is not quite 150W.?
Running the amp on 240 AC, It "talks" up to around 1400W PEP (output)? measured with both the? Array Solutions Power Master II and the peak reading watt-meter in the Palstar HF-Auto tuner.
I get signal reports similar to what the Viking 500 guys get in the Pacific NW
Driving it with any other NON-carrier controlled AM driver would require up to 375W of "resting" (or steady ) carrier to even come close to the above PEP
The 3-500's do also show some "color" when operating on AM.? I also tried a pair of 3-400's (that I have for my Loudenboomer) and they produced identical results.
Now having said all that, I never do "Lock-to-Talk" AM for 20min or even 10min like some of my "Verbose" friends do!? In fact, when I pause, I drop the carrier.?
But if I stop talking the power output still drops to a little less than 150W
I don't think anyone has ever told me that they could tell I was using Carrier Controlled AM unless I mentioned it.
And I actually would rather use my Viking Valiant anyway.?
Besides, 450W PEP with the Valiant and the 1300-1400W PEP running the C-Line / L-4B is only about a 5db difference and not really worth it.
73/Rick
W4XA
*Every post is created using Linux
-- 73 -Jim NU0C
|
Jim Shorney
Paul Christensen
K8CCA