Re: PS Cap Replacement Guidelines
I was automatically replacing can caps but I've backed-off from that.? There are some Drake sets that I have found need to have the can replaced almost certainly.? These are the TR-4's and especially the TR-4C(any).? For some reason, these have failed a number of times for me.? I've also had issues with the cans in the T-4(any).
I have just run three 2-B's across my bench and they all were performing fine with no excessive hum.
Should you decide to test first, by all means test and replace any that do not meet spec -- even if "on the edge"
Steve Wedge, W1ES/4
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
------- Original Message -------
On Thursday, May 25th, 2023 at 1:56 PM, Dan <pitfit@...> wrote:
So what rules do you follow when considering replacing p.s. filter caps? In general, I've been pretty much making it one of the few "gotta-do's" in my work - but I wonder. Replacement caps, whether the Hayseed all-in-one can type or discrete, individual caps are inexpensive and pretty straight forward to mount.
I have a really nice 2-B here and I have the Hayseed can all ready to go. However, the radio functions fine, no hum at all. Of the four p.s. terminals on the existing can three measure 120 Hz. ac way, way down in the millivolt range. The worst of the four shows about 0.5 VAC riding on 150 VDC or about 0.3% ripple (AC RMS/VDC X 100). Tube pin voltages are all at spec. It's a happy radio. With those values and no hum if this were a five year old radio I wouldn't even be considering a p.s. cap replacement.
The can >is< about 60+ years old however. Do most of you replace it anyway to avoid the risk of an age related catastrophic failure one day?
Dan
WB4GRA
|
I've seen pictures of 2Bs with the S meter sitting not on S1 with the power off. Here's one at WB4HFN's web site:
Mine is an early serial number 2974.
Ken, VE3FIT
|
On 2023-05-25 12:30, GARY WINBLAD wrote: I've never had a TR-7 so am interested, might get one someday.
I don't think it is fully synthesized though...
meaning the PTO doesn't have anything to do with LOCK.. Hi Gary, *** No, it's not fully synthesized. But the PTO has everything to do with lock. The PTO output is mixed with another oscillator - also there's a divide-by-N chain. A voltage controlled oscillator outputs between 48.05MHz to 78.05Mhz, providing high-side injection to mix the incoming signal up to the first IF of 48.05Mhz. The PTO output is mixed with a 40Mhz crystal reference oscillator to get a 45.05 to 45.55Mhz signal. The 45.05-45.55Mhz signal is mixed with the voltage controlled oscillator to produce a 3.0 - 33.0Mhz signal. The 3.0-33.0Mhz signal is divided by a divide-by-N circuit to get 500kHz. THe 500kHz is compared with the 500kHz from the reference oscillator ( divided down from 40Mhz ). So - it is a sort of synthesizer - a phase locked loop. One of the inputs to the PLL is the VFO signal. Drake had this good PTO that they had developed over the years. Same one as in the TR4 etc. So they leveraged that technology. Aside from this unlocking problem, it's a really stable, solid radio. I can detect no drift, at least on SSB. - Jerry, KF6VB A common mod I have heard is an X-Lock (huff and puff) stabilizer,
is this what you are working on?
73,
Gary
WB6OGD
On 05/25/2023 12:20 PM PDT jerry-KF6VB <jerry@...> wrote:
On 2023-05-24 18:52, Gary Follett wrote:
Is the out-of-lock condition present on all bands? It it present in
both receive and transmit? Interesting. A light tap on the tuning knob can make it drop out of
lock.
In receive OR transmit. If, however, I take it out of lock on transmit,
it pops back into lock when I let go of the PTT. And if I take it out
of
lock in receive, it pops back into lock when I put it into transmit.
A much heaver tap on the top cover - actually a fist punch - will take
it out of lock also. It takes a much lighter one-finger tap on the
tuning knob
though.
Light taps elsewhere on the panel have no effect.
OK...I just removed the top & bottom covers. Removed the DR-7 display
card and
replaced it with the jumper card. Unscrewed the front panel & folded it
down.
Started spudging at the VFO wires with a bamboo skewer ( nonconductive,
won't
short anything out ).
Results are inconclusive. Spudging the wires at the PTO made changes
for a while,
now they don't. But I can reliably get it to drop out of lock by
turning the tuning
knob to its stop.
And here's a really interesting little factoid: I can get lock back by
cycling power...
with the switch on the POWER SUPPLY. Without touching anything on the
radio itself. For
me, this points to an electronic problem - not just cracked solder
joints. Maybe a carbon
comp resistor has drifted up enough to make the VFO marginal? This
happened to me with a
Heathkit SB-610 monitor scope; the two-tone oscillator was INOP.
Multiple resistors had
drifted out of tolerance. Replaced them all, and *poof*... one working
SB-610.
Time to get out some test equipment. Can anybody supply a clue as to
which wire is which?
The PTO should have 4 wires: Power, Ground, Output, & RIT. There are
the following wires
coming out of it:
* A white-with-green-stripe coming out the side.
* A orange wire coming out the bottom
* A light green wire coming out the bottom. This one seems the most
sensitive to spudging.
For now, I put it together. I have another PTO coming in from Ebay,
and I'll mess with
that first.
- Jerry, KF6VB
Often the out-of-lock condition is simply dirty switches in the PTO
selection path. That includes the pushbuttons that affect fixed, Pro
etc. as well as the rotary switch for using the AUX-7 options.
The fact that a tap on the PTO brings it back to life does not mean
the PTO is bad, as a very light tap anywhere on the front panel will
often make the dirty switch contacts work.
Also dirty PC board connectors can cause this.
Gary
W0DVN
On May 24, 2023, at 12:27 PM, jerry-KF6VB <jerry@...> wrote:
All,
I note that the TR7 doesn't have as much talk power as my more
modern rigs. No built in speech compression.
So I just scored an SP75 speech processor on Ebay. An impressive
device, judging from the schematic. Basically, it's an SSB
transmitter -> clipper -> receiver arrangement. I used to have a
Kenwood TS-830S that had similar, and it worked
very well.
This thing should give a boost similar to adding a linear.
But what about a linear? My homebrew 1100W LDMOS requires band
data. I could...
* Modify the linear for setting the band manually. In this case,
sooner or later in the heat of battle I will transmit on the wrong
band. The LDMOS is protected by a pair of tandem matches - one before
the LPF, the other after. It should be
adequately protected. But the device cost me $230! And it's soldered
to the heat spreader, would be a real PITA to replace!
* Modify the TR7 to produce band data. I could build it into a
homemade Aux7 module. Pop a cable out through the
fan 110V hole. Make a little bracket to hold an 8-pin "aviation"
connector matching the one I used on the linear. No
extra holes in the radio, all reversible.
* Haul the Alpha 78 out of the shed. It's big, loud and heavy.
* Haul the Collins 30L-1 out of the shed. Smaller than the Alpha, not
quite as loud, not as heavy. Been years since I ran it though. Need
to reform the electrolytics. Where did I leave that Variac?
The intermittant VCO unlocking has continued. I suspect the PTO. A
strategic tap on the main tuning knob will unlock it. Another PTO is
on order. Cheapest one on Ebay. I should be able to play with it on
the bench, and if it's good, I can swap it in. Per the schematic,
it's not very complicated - just a JFET oscillator - split capacitor,
I guess that makes it a Colpitts. A tap on the variable inductor
feeds a BJT common-emitter amplifier which feeds a low pass filter.
There's a 10uF electrolytic inside; wonder if those ever fail? It
feels to me more like a cracked solder joint.
- Jerry, KF6VB
|
Re: Free Drake B-Line Tubes (about ~$300 in tubes)
Sounds good David, I¡¯ll work with you directly.
Sean KK6BEB?
I will take them all.? Tell me how much postage to 70435. Thanks David Assaf III
W5XU??? VP8RXU
On Thu, May 25, 2023, 2:34 PM Sean (KK6BEB) < seanlynch@...> wrote: First come first?serve...
Hey gang, in ~2014 I purchased a quantity of 2 "Primo Complete Tube Sets" from? for the Drake R4-B. Their primo rating means all tubes tested good. I *also purchased 1?"Primo Complete Tube Set" (minus finals) for the T-4XB.
I don't currently have a B-Line and the tubes are just sitting here. If you cover shipping and handling, I'd be happy to ship them to you from Los Angeles. I'd prefer to ship everything to one person rather that piecemeal?
If you have any ham stuff you want to give me in exchange, great, but not necessary.
73, KK6BEB Sean
|
Re: Free Drake B-Line Tubes (about ~$300 in tubes)
I will take them all.? Tell me how much postage to 70435. Thanks David Assaf III
W5XU??? VP8RXU
On Thu, May 25, 2023, 2:34 PM Sean (KK6BEB) < seanlynch@...> wrote: First come first?serve...
Hey gang, in ~2014 I purchased a quantity of 2 "Primo Complete Tube Sets" from? for the Drake R4-B. Their primo rating means all tubes tested good. I *also purchased 1?"Primo Complete Tube Set" (minus finals) for the T-4XB.
I don't currently have a B-Line and the tubes are just sitting here. If you cover shipping and handling, I'd be happy to ship them to you from Los Angeles. I'd prefer to ship everything to one person rather that piecemeal?
If you have any ham stuff you want to give me in exchange, great, but not necessary.
73, KK6BEB Sean
|
Free Drake B-Line Tubes (about ~$300 in tubes)
First come first?serve...
Hey gang, in ~2014 I purchased a quantity of 2 "Primo Complete Tube Sets" from? for the Drake R4-B. Their primo rating means all tubes tested good. I *also purchased 1?"Primo Complete Tube Set" (minus finals) for the T-4XB.
I don't currently have a B-Line and the tubes are just sitting here. If you cover shipping and handling, I'd be happy to ship them to you from Los Angeles. I'd prefer to ship everything to one person rather that piecemeal?
If you have any ham stuff you want to give me in exchange, great, but not necessary.
73, KK6BEB Sean
|
I've never had a TR-7 so am interested, might get one someday.
I don't think it is fully synthesized though...
meaning the PTO doesn't have anything to do with LOCK..
A common mod I have heard is an X-Lock (huff and puff) stabilizer,
is this what you are working on?
73,
Gary
WB6OGD
toggle quoted message
Show quoted text
On 05/25/2023 12:20 PM PDT jerry-KF6VB <jerry@...> wrote:
On 2023-05-24 18:52, Gary Follett wrote:
Is the out-of-lock condition present on all bands? It it present in
both receive and transmit? Interesting. A light tap on the tuning knob can make it drop out of
lock.
In receive OR transmit. If, however, I take it out of lock on transmit,
it pops back into lock when I let go of the PTT. And if I take it out
of
lock in receive, it pops back into lock when I put it into transmit.
A much heaver tap on the top cover - actually a fist punch - will take
it out of lock also. It takes a much lighter one-finger tap on the
tuning knob
though.
Light taps elsewhere on the panel have no effect.
OK...I just removed the top & bottom covers. Removed the DR-7 display
card and
replaced it with the jumper card. Unscrewed the front panel & folded it
down.
Started spudging at the VFO wires with a bamboo skewer ( nonconductive,
won't
short anything out ).
Results are inconclusive. Spudging the wires at the PTO made changes
for a while,
now they don't. But I can reliably get it to drop out of lock by
turning the tuning
knob to its stop.
And here's a really interesting little factoid: I can get lock back by
cycling power...
with the switch on the POWER SUPPLY. Without touching anything on the
radio itself. For
me, this points to an electronic problem - not just cracked solder
joints. Maybe a carbon
comp resistor has drifted up enough to make the VFO marginal? This
happened to me with a
Heathkit SB-610 monitor scope; the two-tone oscillator was INOP.
Multiple resistors had
drifted out of tolerance. Replaced them all, and *poof*... one working
SB-610.
Time to get out some test equipment. Can anybody supply a clue as to
which wire is which?
The PTO should have 4 wires: Power, Ground, Output, & RIT. There are
the following wires
coming out of it:
* A white-with-green-stripe coming out the side.
* A orange wire coming out the bottom
* A light green wire coming out the bottom. This one seems the most
sensitive to spudging.
For now, I put it together. I have another PTO coming in from Ebay,
and I'll mess with
that first.
- Jerry, KF6VB
Often the out-of-lock condition is simply dirty switches in the PTO
selection path. That includes the pushbuttons that affect fixed, Pro
etc. as well as the rotary switch for using the AUX-7 options.
The fact that a tap on the PTO brings it back to life does not mean
the PTO is bad, as a very light tap anywhere on the front panel will
often make the dirty switch contacts work.
Also dirty PC board connectors can cause this.
Gary
W0DVN
On May 24, 2023, at 12:27 PM, jerry-KF6VB <jerry@...> wrote:
All,
I note that the TR7 doesn't have as much talk power as my more
modern rigs. No built in speech compression.
So I just scored an SP75 speech processor on Ebay. An impressive
device, judging from the schematic. Basically, it's an SSB
transmitter -> clipper -> receiver arrangement. I used to have a
Kenwood TS-830S that had similar, and it worked
very well.
This thing should give a boost similar to adding a linear.
But what about a linear? My homebrew 1100W LDMOS requires band
data. I could...
* Modify the linear for setting the band manually. In this case,
sooner or later in the heat of battle I will transmit on the wrong
band. The LDMOS is protected by a pair of tandem matches - one before
the LPF, the other after. It should be
adequately protected. But the device cost me $230! And it's soldered
to the heat spreader, would be a real PITA to replace!
* Modify the TR7 to produce band data. I could build it into a
homemade Aux7 module. Pop a cable out through the
fan 110V hole. Make a little bracket to hold an 8-pin "aviation"
connector matching the one I used on the linear. No
extra holes in the radio, all reversible.
* Haul the Alpha 78 out of the shed. It's big, loud and heavy.
* Haul the Collins 30L-1 out of the shed. Smaller than the Alpha, not
quite as loud, not as heavy. Been years since I ran it though. Need
to reform the electrolytics. Where did I leave that Variac?
The intermittant VCO unlocking has continued. I suspect the PTO. A
strategic tap on the main tuning knob will unlock it. Another PTO is
on order. Cheapest one on Ebay. I should be able to play with it on
the bench, and if it's good, I can swap it in. Per the schematic,
it's not very complicated - just a JFET oscillator - split capacitor,
I guess that makes it a Colpitts. A tap on the variable inductor
feeds a BJT common-emitter amplifier which feeds a low pass filter.
There's a 10uF electrolytic inside; wonder if those ever fail? It
feels to me more like a cracked solder joint.
- Jerry, KF6VB
|
On 2023-05-24 18:52, Gary Follett wrote: Is the out-of-lock condition present on all bands? It it present in
both receive and transmit? Interesting. A light tap on the tuning knob can make it drop out of lock. In receive OR transmit. If, however, I take it out of lock on transmit, it pops back into lock when I let go of the PTT. And if I take it out of lock in receive, it pops back into lock when I put it into transmit. A much heaver tap on the top cover - actually a fist punch - will take it out of lock also. It takes a much lighter one-finger tap on the tuning knob though. Light taps elsewhere on the panel have no effect. OK...I just removed the top & bottom covers. Removed the DR-7 display card and replaced it with the jumper card. Unscrewed the front panel & folded it down. Started spudging at the VFO wires with a bamboo skewer ( nonconductive, won't short anything out ). Results are inconclusive. Spudging the wires at the PTO made changes for a while, now they don't. But I can reliably get it to drop out of lock by turning the tuning knob to its stop. And here's a really interesting little factoid: I can get lock back by cycling power... with the switch on the POWER SUPPLY. Without touching anything on the radio itself. For me, this points to an electronic problem - not just cracked solder joints. Maybe a carbon comp resistor has drifted up enough to make the VFO marginal? This happened to me with a Heathkit SB-610 monitor scope; the two-tone oscillator was INOP. Multiple resistors had drifted out of tolerance. Replaced them all, and *poof*... one working SB-610. Time to get out some test equipment. Can anybody supply a clue as to which wire is which? The PTO should have 4 wires: Power, Ground, Output, & RIT. There are the following wires coming out of it: * A white-with-green-stripe coming out the side. * A orange wire coming out the bottom * A light green wire coming out the bottom. This one seems the most sensitive to spudging. For now, I put it together. I have another PTO coming in from Ebay, and I'll mess with that first. - Jerry, KF6VB Often the out-of-lock condition is simply dirty switches in the PTO
selection path. That includes the pushbuttons that affect fixed, Pro
etc. as well as the rotary switch for using the AUX-7 options.
The fact that a tap on the PTO brings it back to life does not mean
the PTO is bad, as a very light tap anywhere on the front panel will
often make the dirty switch contacts work.
Also dirty PC board connectors can cause this.
Gary
W0DVN
On May 24, 2023, at 12:27 PM, jerry-KF6VB <jerry@...> wrote:
All,
I note that the TR7 doesn't have as much talk power as my more modern rigs. No built in speech compression.
So I just scored an SP75 speech processor on Ebay. An impressive device, judging from the schematic. Basically, it's an SSB transmitter -> clipper -> receiver arrangement. I used to have a Kenwood TS-830S that had similar, and it worked
very well.
This thing should give a boost similar to adding a linear.
But what about a linear? My homebrew 1100W LDMOS requires band data. I could...
* Modify the linear for setting the band manually. In this case, sooner or later in the heat of battle I will transmit on the wrong band. The LDMOS is protected by a pair of tandem matches - one before the LPF, the other after. It should be
adequately protected. But the device cost me $230! And it's soldered to the heat spreader, would be a real PITA to replace!
* Modify the TR7 to produce band data. I could build it into a homemade Aux7 module. Pop a cable out through the
fan 110V hole. Make a little bracket to hold an 8-pin "aviation" connector matching the one I used on the linear. No
extra holes in the radio, all reversible.
* Haul the Alpha 78 out of the shed. It's big, loud and heavy.
* Haul the Collins 30L-1 out of the shed. Smaller than the Alpha, not quite as loud, not as heavy. Been years since I ran it though. Need to reform the electrolytics. Where did I leave that Variac?
The intermittant VCO unlocking has continued. I suspect the PTO. A strategic tap on the main tuning knob will unlock it. Another PTO is on order. Cheapest one on Ebay. I should be able to play with it on the bench, and if it's good, I can swap it in. Per the schematic, it's not very complicated - just a JFET oscillator - split capacitor, I guess that makes it a Colpitts. A tap on the variable inductor feeds a BJT common-emitter amplifier which feeds a low pass filter.
There's a 10uF electrolytic inside; wonder if those ever fail? It feels to me more like a cracked solder joint.
- Jerry, KF6VB
|
Re: PS Cap Replacement Guidelines
I haven¡¯t seen Postage Stamp capacitors for decades ¨C they must not be making them anymore.? I recently talked to a (young-ish..) electronics engineer that showed me a pic of one and asked me if I knew what it was.? (It was in a very old radio, and I guess he thought I would know¡) ? Terry K7WLD Wenatchee, WA ?
toggle quoted message
Show quoted text
From: [email protected] < [email protected]> On Behalf Of Dan Sent: Thursday, May 25, 2023 10:57 AM To: [email protected]Subject: [DRAKE-RADIO] PS Cap Replacement Guidelines ? So what rules do you follow when considering replacing p.s. filter caps? In general, I've been pretty much making it one of the few "gotta-do's" in my work - but I wonder. Replacement caps, whether the Hayseed all-in-one can type or discrete, individual caps are inexpensive and pretty straight forward to mount.
I have a really nice 2-B here and I have the Hayseed can all ready to go. However, the radio functions fine, no hum at all. Of the four p.s. terminals on the existing can three measure 120 Hz. ac way, way down in the millivolt range. The worst of the four shows about 0.5 VAC riding on 150 VDC or about 0.3% ripple (AC RMS/VDC X 100). Tube pin voltages are all at spec. It's a happy radio. With those values and no hum if this were a five year old radio I wouldn't even be considering a p.s. cap replacement.
The can >is< about 60+ years old however. Do most of you replace it anyway to avoid the risk of an age related catastrophic failure one day?
Dan
WB4GRA
|
Re: 2-B's and related Stuff Available
I haven¡¯t tried this in a 2-B but I know that swapping in a 6EA8 in a Collins set makes it work better. I may try in my keeper, just for curiosity.?
73,
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail for iOS
On Thu, May 25, 2023 at 12:54, < ve3fit@...> wrote: On Wed, May 24, 2023 at 09:00 AM, Steve Wedge, W1ES/4 wrote:
2-B No. 2.? Complete and aligned.? All tubes screened with Hickok 6000B and weak ones were replaced.? Works great and comes with the calibrator.? Chassis was cleaned and probably a 7/10, with some spotting.? Has crystals that were provided by factory.? $200 plus shipping.
Hi Steve. I foolishly sold my Hickook 539 tube tester a few years ago. I was through with tube gear, right? All that I have available right now are several GOOD/BAD emissions testers. Could you give us some words of wisdom regarding checking tubes that may be 60 years old. My new-to-me 2B seems to be low on gain even after a careful re-alignment, so the tubes are the obvious area to investigate. I did find a leaky 6U8 through DC voltage checks. It's control grid was going positive and completely messing up the AVC line. An NOS replacement set that right. Thanks and 73.
Ken, VE3FIT
|
Re: PS Cap Replacement Guidelines
I usually just change them as I don't want to keep re-working old radios.? I have a Heathkit cap tester and I can say that I used to test them all, but rarely do anymore.? I am not sure if I have ever tested an electrolytic or wax paper cap that was even close to its voltage rating, that was not leaking.? Of course some are worse than others, but they are all leaky these days.? ?All electrolytics, bumblebee, black beauties, waxies, etc are destined for the trash at my house.??
As far as using Hayseed cans or discreet caps, I have done a few hayseed caps, but I prefer?to have the original?can gutted and new caps stuffed inside or mounted on terminal strips below the chassis if there is room.? After I get the rig up and running I look to see if any of the micas or ceramics are bad.? Most of the time they are not, but sometimes you find bad ones.? On the Collins 75A-4 that I am working on right now, there was a ceramic?cap mounted to the incoming power line that was blown in half, (are these the old caps called death caps?) so I replaced that with the proper? Y2 type cap.?
|
Re: PS Cap Replacement Guidelines
I thought I was the only one with a 2B and an unused Hayseed replacement cap for it.? I think I bought it from someone on this list who wasn't going to use it.
Like yours, my 2B seems happy and hum-free enough for now.? If that changes, then I'll address the problem (and hopefully haven't lost the replacement cap by then).
Thanks,
Barry - N4BUQ
From: "Dan" <pitfit@...>
To: "DRAKE-RADIO" <[email protected]>
Sent: Thursday, May 25, 2023 12:56:38 PM
Subject: [DRAKE-RADIO] PS Cap Replacement Guidelines
So what rules do you follow when considering replacing p.s. filter caps? In general, I've been pretty much making it one of the few "gotta-do's" in my work - but I wonder. Replacement caps, whether the Hayseed all-in-one can type or discrete, individual caps are inexpensive and pretty straight forward to mount.
I have a really nice 2-B here and I have the Hayseed can all ready to go. However, the radio functions fine, no hum at all. Of the four p.s. terminals on the existing can three measure 120 Hz. ac way, way down in the millivolt range. The worst of the four shows about 0.5 VAC riding on 150 VDC or about 0.3% ripple (AC RMS/VDC X 100). Tube pin voltages are all at spec. It's a happy radio. With those values and no hum if this were a five year old radio I wouldn't even be considering a p.s. cap replacement.
The can >is< about 60+ years old however. Do most of you replace it anyway to avoid the risk of an age related catastrophic failure one day?
Dan
WB4GRA
|
PS Cap Replacement Guidelines
So what rules do you follow when considering replacing p.s. filter caps? In general, I've been pretty much making it one of the few "gotta-do's" in my work - but I wonder. Replacement caps, whether the Hayseed all-in-one can type or discrete, individual caps are inexpensive and pretty straight forward to mount.
I have a really nice 2-B here and I have the Hayseed can all ready to go. However, the radio functions fine, no hum at all. Of the four p.s. terminals on the existing can three measure 120 Hz. ac way, way down in the millivolt range. The worst of the four shows about 0.5 VAC riding on 150 VDC or about 0.3% ripple (AC RMS/VDC X 100). Tube pin voltages are all at spec. It's a happy radio. With those values and no hum if this were a five year old radio I wouldn't even be considering a p.s. cap replacement.
The can >is< about 60+ years old however. Do most of you replace it anyway to avoid the risk of an age related catastrophic failure one day?
Dan
WB4GRA
|
Re: 2-B's and related Stuff Available
On Wed, May 24, 2023 at 09:00 AM, Steve Wedge, W1ES/4 wrote:
2-B No. 2.? Complete and aligned.? All tubes screened with Hickok 6000B and weak ones were replaced.? Works great and comes with the calibrator.? Chassis was cleaned and probably a 7/10, with some spotting.? Has crystals that were provided by factory.? $200 plus shipping.
Hi Steve. I foolishly sold my Hickook 539 tube tester a few years ago. I was through with tube gear, right? All that I have available right now are several GOOD/BAD emissions testers. Could you give us some words of wisdom regarding checking tubes that may be 60 years old. My new-to-me 2B seems to be low on gain even after a careful re-alignment, so the tubes are the obvious area to investigate. I did find a leaky 6U8 through DC voltage checks. It's control grid was going positive and completely messing up the AVC line. An NOS replacement set that right. Thanks and 73. Ken, VE3FIT
|
Re: R-4C wire with no end stop
Primarily shielding for the troublesome 6EJ7 third mixer.?
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail for iOS
On Thu, May 25, 2023 at 09:26, Peter Ravn via groups.io < fasan5@...> wrote: What's the idea of the metal cover on top of the filter switch? The cover is not seen in all R4C's.
Thanks.
Peter OZ8CTH
|
On 2023-05-24 19:12, Jim Shorney wrote: Could also be bogus band data from a dirty bandswitch. *** Sure could. I have gone over all the switches and every last Molex with DeOxit. HOWEVER: I can easily make it lose lock by tapping the main tuning knob. I cannot make it lose lock by tapping anything else. - Jerry, KF6VB
|
Re: TR4C With Unusual V3 Screen Resistor
Thank you Richard.? I also have the TR4C service cd and it lists 100K as the screen resistor, and this agrees with a TR4CW I just opened up.? Over the years, from the TR3 to the TR4C, I think they changed the biasing on this tube.? Now I am really curious to take a look at all the schematics and parts lists I have, along with the CD's.? I am even more curious now.? I will let the group know what I find, and that way it will be chronicled on this reflector for the future.? THANKS AGAIN EVERYONE!
73
Mark
N5KAE
|
Re: R-4C wire with no end stop
What's the idea of the metal cover on top of the filter switch? The cover is not seen in all R4C's.
Thanks.
Peter OZ8CTH
|
Re: 2-B's and related Stuff Available
Steve Good morning? I sent you an email about the 2BQ off list but I got a message about a server failure. Let me know if you got it. Bill
toggle quoted message
Show quoted text
On May 24, 2023, at 9:43 PM, Steve Wedge, W1ES/4 via groups.io <w1es@...> wrote:
? The parts rig? ?Yep. I¡¯ll hold it for you and get figures tomorrow.?
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail for iOS
On Wed, May 24, 2023 at 21:16, wb6ogd < garywinblad@...> wrote: Steve,Is 2B no. 1 still available? If so, I want it. ?Shipping is to 95762.
73, Gary? WB6OGD?
On May 24, 2023, at 5:53 PM, Steve Wedge, W1ES/4 via groups.io <w1es@...> wrote:
? My QTH is good in QRZ. Please send your zip/address and I¡¯ll get a shipping quote. Inside NC, it should??be pretty low
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail for iOS
On Wed, May 24, 2023 at 19:24, Steve Wedge, W1ES/4 via groups.io < w1es@...> wrote:
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail for iOS
On Wed, May 24, 2023 at 18:34, william stevens <197174stevens@...> wrote: SteveI will take the 2bq if still available icanpay by MO or check. Thanks Bill WB2UFC? On May 24, 2023, at 4:27 PM, Ronald Beaver <Ronaldbeaver1320@...> wrote:
? Hey Steve, I'm interested in the 2AC calibrator.? Is the chassis ok?
Thanks, Ron Beaver WB4OQL Clyde, NC On Wed, May 24, 2023 at 12:00?PM Steve Wedge, W1ES/4 via <w1es= [email protected]> wrote: Fellow Drake fans --
I am almost done redoing the 2-B that I'm going to keep and need to move the others along.? They are as described:
2-B No. 1, Mostly Complete.? It receives but haven't tested how well.? Chassis good compared with most (some spots).? Slug carriage doesn't want to move when knob is attached.? Missing dial cord and the pointer for same.? All the tubes are with it.?Q Mult connector was scavenged but I have a replacement that's close that I will include. Crystals for 20 and 10 (2) only.? I was going to keep this for parts but it will make a good receiver if you have the right parts and metalworking skills.?$75 + shipping.?
2-B No. 2.? Complete and aligned.? All tubes screened with Hickok 6000B and weak ones were replaced.? Works great and comes with the calibrator.? Chassis was cleaned and probably a 7/10, with some spotting.? Has crystals that were provided by factory.? $200 plus shipping.
2-BQ Q Multiplier.? Works fine.? Cabinet has some rust and could stand a repaint.? Aligned.? These things make what is already a surprisingly good (for 1962) CW receiver into an excellent receiver.? $80 plus shipping.
2-AC Calibrator.? Works with 2-A, 2-B, 2-C.? works great. $75 plus shipping.
I use Pirate Ship, so shipping rates are pretty reasonable.? I prefer a cheque or PP F&F.? If I know you from? being on here, we're good with personal cheques.? Unlike if I sell them on that auction site, I stand behind these amongst the folks on this reflector.
I'm clearing some space so I can do some woodworking again :-)
COMING SOON: I have two R-4A's (one 11-tube and one 13-tube).? They're working but I haven't tested them yet.? The 11-tube one has a dead AC switch that I'll bypass.? Seem to be working on all bands.? If you're interested, let me know and/or make offers.? They're in decent shape but not museum quality by any stretch.
I will also have either a 2-BQ or a 2-AQ.? I'm torn because the -AQ is in better shape but has the smaller speaker.??
More to come.? Like I said, clearning some stuff out and I will be also using the money to buy a new "modern" rig to replace my K3/P3...
73,
Steve Wedge, W1ES/4
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
|
Make sure the CXR OSC inside the SP-75 is tweaked for your voice + mic.? ? You can do this by monitoring urself on an outboard RX.? ?You gotta tweak it just right.?
6-9 db of clipping is ample.? Go any higher than 12 db, and the noise gate? will be stuck wide open.? With the clipping level at 6-9db, tweak the noise gate threshold very carefully.?
Once that's all done,? it will run real smooth on VOX.? ? ?Talk power...without distortion, and the noise gate will kill any background noise.?
|
David
Gary WB6OGD
K8CCA