2-B AGC voltage ¡ª possibly resolved
I checked into the Sunday net today and Jeff, WA8SAJ, suggested that I check?the RF GAIN pot. This is a 15M (!) pot and is not very easy to find, these days.?
I measured the pot across the entire part, since there¡¯s one end that isn¡¯t connected to anything.?
The pot measured 26M ohms.?
My parts receiver¡¯s pot measures 20M, as does my good 2-B. These parts obviously appear to age by getting more and more resistive.?
I should be able to get this 2-B to meet spec with the pot at 20M. With these resistances so very high, one can¡¯t really set the resistance to 15M ohms directly but we can set it indirectly by measuring the total resistance and subtracting 15M from it, then setting the resistance from the wiper to the open end to the value of the difference. One can then set up the sensitivity with the pot at 15M, which is what the value should be with the RF GAIN fully CW.?
It not the best way but it¡¯s a workaround for this nearly Unobtanium part as it ages.?
Thanks again, Jeff!
73,
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail for iOS
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Re: Remove case from MN 2000
Bob
Do not remove the front panel screws!
Put the feet back on their screws. Not going to be easy now but you should try and get the feet started on the thread, then pull on it to keep the screw from rotating and finger tighten the feet as much as you can.
Remove any other screws in the bottom of the cabinet. Six as I recall???
Push the front panel towards the ?rear and remove the tuner box as one unit though this is typically quite tight. If someone has not used the original screws on the inner cover this can be REALLY tough! You will hear some scraping.
If the top, bottom, or sides have been compressed inwards, this will also complicate removal of the inner box. Try to straighten it as best you can.
Good luck!
73 Peter VE7PS?
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On May 7, 2023, at 6:54 PM, K6OXN Bob <bobk6oxn@...> wrote:
?I assume it slides out the front of the unit. But it is really tight.
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Re: Remove case from MN 2000
I assume it slides out the front of the unit. But it is really tight.
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Re: Remove case from MN 2000
I have the feet off. The screws that hold the feet are still in place tho.
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Re: Remove case from MN 2000
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On May 7, 2023, at 7:42 PM, K6OXN Bob <bobk6oxn@...> wrote:
Ok I will bite. How do you remove the case from an MN 2000 antenna tuner. There seems to be screws near the feet but of course they don't come out. 2 screws on the bottom and 4 sheet metal screws on the front panel.? How do I get the case off to tighten the feet screws and check the inside before using it? It is built like a tank.
73? Bob K6OXN
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Ok I will bite. How do you remove the case from an MN 2000 antenna tuner. There seems to be screws near the feet but of course they don't come out. 2 screws on the bottom and 4 sheet metal screws on the front panel.? How do I get the case off to tighten the feet screws and check the inside before using it? It is built like a tank.
73? Bob K6OXN
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Re: DRAKE TECHNICAL NET ( May 7, 2023 )
On 2023-05-07 15:29, M Gilger wrote: Evan, K9SQG was our net control for today's 7.238 tech net. We had to
run the net on 7.241 due to 7.238 being occupied. The band was in
terrible shape overall. Is this mostly an East Coast thing? I was listening, nothing heard. What time does it run, in UTC? I read "4:00pm EST / 3:00PM CST". Does it change for daylight savings time? - Jerry, KF6VB
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DRAKE TECHNICAL NET ( May 7, 2023 )
Evan, K9SQG was our net control for today's 7.238 tech net. We had to run the net on 7.241 due to 7.238 being occupied. The band was in terrible shape overall.?
There were 18 stations participating using the following equipment.?
B line: ?1 C line: ?2 TR4: ?2 TR5: ?5 TR7: ?5 Other: ?3
73's, Mark, WB0IQK
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Re: white line on 7 line knobs
Markal paint sticks have been around for many years and are available on ebay for cheap
John
On Sun, May 7, 2023 at 11:56?AM KL7AM < w7apm@...> wrote: I have found whiteout as used for typing or writing on paper to work very well
KL7AM
----- Original Message -----
From: "Karl du Roi, DK7AL" <dk7al@...>
To: "DRAKE-RADIO" <[email protected]>
Sent: Sunday, May 7, 2023 5:05:05 AM
Subject: Re: [DRAKE-RADIO] white line on 7 line knobs
For such refurbish tasks I have simply taken some colour tins from
Revell M5 or SM301 (white, not shiny) from the nearest hobby shop
dealing with plastic models. The varnish can be applied into the recess
of the knobs as described earlier in this subject.
Best regards.
Karl, DK7AL
On 07.05.23 14:09, Steve Wedge, W1ES/4 via wrote:
> Another thing to consider is that if you clean the knobs in an ultrasonic cleaner, the paint will be gone when you¡¯re done.
>
> I¡¯ve been using the putty stick to bring the lines and dots back but am considering going back to paint. Paint is the only way for 2 Line knobs.
>
> Steve Wedge, W1ES/4
>
> Time flies like an arrow. Fruit flies like a banana.
>
> Sent from Proton Mail for iOS
>
> On Sat, May 6, 2023 at 22:52, Evan via <[k9sqg=[email protected]](mailto:On Sat, May 6, 2023 at 22:52, Evan via <<a href=)> wrote:
>
>> Jerry,
>>
>> Sounds like you are making good progress.
>>
>> As to the knobs, one of the antique radio vendors sells a white "putty stick" which one can rub onto/into the indicator lines on the knobs. After rubbing in, the excess can be wiped off with a cloth. For the perfectionist, white paint can be used to repaint the pointers. Sometimes just soaking in soap water and light brushing can restore the brightness but rubbing too hard can remove the paint.
>>
>> 73,
>>
>> Evan, K9SQG
>>
>> -----Original Message-----
>> From: jerry-KF6VB <jerry@...>
>> To: [email protected]
>> Sent: Sat, May 6, 2023 10:06 pm
>> Subject: [DRAKE-RADIO] TR7 Filters and Knobs
>>
>> So today a care package arrived from Noble Radio. A 450Hz CW filter. A
>> true work of art. I did not delay in installing it. Had to do some
>> cleanup on the filter card; somebody had done a messy remove of its
>> original filters - all except the standard 2.3kHz SSB filter. Possibly
>> my Ebay seller. After all, why sell an INOP rig full of expensive
>> separately-saleable filters?
>>
>> It works great. Single-signal CW reception.
>>
>> While I was in there, I did the mod that lets the carrier control work
>> with SSB. It's just one wire tacked to two
>> terminals on the mode switch.
>>
>> I also fixed the loose coax terminal I mentioned earlier. It turned
>> out that the "clip" part had come undone. Now
>> it's nice & tight.
>>
>> Then I did something purely cosmetic: pulled off all the knobs and
>> treated them to an ultrasonic cleaner bath.
>> Except for the Mode switch and the Aux Program switch. Those don't seem
>> to have setscrews. How do they come off?
>>
>> The white paint inside some of the pointer knobs - white paint inside
>> a groove - is a bit discolored and perished.
>> I may want to redo it.
>>
>> - Jerry, KF6VB
>>
>>
>
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Re: TR7 Filters and Knobs
Now that you mentioned it, I remember seeing this product.
73,
Steve Wedge, W1ES/4
Time flies like an arrow.? Fruit flies like a banana.
Sent with Proton Mail secure email.
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------- Original Message ------- On Sunday, May 7th, 2023 at 3:05 PM, jerry-KF6VB <jerry@...> wrote: On 2023-05-07 10:16, Steve Wedge, W1ES/4 via groups.io wrote:
I am fairly certain that the discs got ruined by the simple green at
50C. It's aggressive on aluminium. *** Now that I remember, there was a dustup some years ago with the
military.
They were washing airplanes with Simple Green, and it was causing
corrosion.
The company developed an alternative:
- Jerry
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Re: TR7 Filters and Knobs
On 2023-05-07 10:16, Steve Wedge, W1ES/4 via groups.io wrote: I am fairly certain that the discs got ruined by the simple green at
50C. It's aggressive on aluminium.
*** Now that I remember, there was a dustup some years ago with the military. They were washing airplanes with Simple Green, and it was causing corrosion. The company developed an alternative: - Jerry
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Re: TR7 Filters and Knobs
I got one off Amazon -- there are many vendors with the identical units. They can time up to an hour and also heat the bath. I've let mine heat up to 50C and that helps with removing stubborn grunge.
That temperature can loosen hot melt glue or other glues, so have a backup plan.
I am fairly certain that the discs got ruined by the simple green at 50C. It's aggressive on aluminium.
73,
Steve Wedge, W1ES/4
Time flies like an arrow.? Fruit flies like a banana.
Sent with Proton Mail secure email.
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------- Original Message ------- On Sunday, May 7th, 2023 at 10:26 AM, jerry-KF6VB <jerry@...> wrote: I didn't put the metal VFO skirt in the bath. I cleaned it with
isopropyl
alcohol and Q-tips. It came out fine; I was worried that the IPA would
take off the paint, but it didn't. The metal disks came out fine.
The VFO skirt had some sort of yellow schmutz on it.
My bath had a few drops of Dawn Ultra.
This ultrasonic cleaner isn't very strong. It's a Harbor Freight
unit.
It will only time to 4 minutes, and it takes maybe 10 shots of that to
clean anything. I've been thinking of retiring it in favor of something
with good reviews on Amazon. There's still a little bit of dirt on the
knobs.
I'll hit them with Q-tips and IPA.
- Jerry
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Re: Drake 2-B Tuning Shaft Bent???
My 2B also had a bent shaft. ?I unstrung the dial and then tapped the shaft back into alignment with light hammer taps while rolling on a flat surface. ?That was the easy part. ?Re-stringing the dial was a real bear!
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On May 7, 2023, at 12:19 PM, Dan <pitfit@...> wrote:
? <image0.jpeg> Dan WB4GRA On May 7, 2023, at 11:38 AM, Dan <pitfit@...> wrote:
?As I continue to evaluate the 2-B on the bench here I'm starting to see 2nd tier issues that were not immediately apparent. In this example, the lathed/machined tuning shaft is slightly bent! What could have caused that without causing other significant physical damage to the radio? It's like finding a bent shaft inside a three layer cake!
I noticed the tuning knob has some slight but noticeable up and down and side to side play when rapidly tuning from low to high on a band - some wobble, not concentric. Then I noticed the same wobble in the shaft itself.
This isn't purely cosmetic-get-used-to-it damage. I now suspect the shaft wobble and resulting plus/minus dial string tension, however small, might be the cause of several brief dial slippages when tuning across a band.
what are the chances of finding a parts unit with a tuning shaft to spare? And I'd rather take a beating than restring the dial.
Comments, advice?
Dan
WB4GRA
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Re: Drake 2-B Tuning Shaft Bent???
 Dan WB4GRA
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On May 7, 2023, at 11:38 AM, Dan <pitfit@...> wrote:
?As I continue to evaluate the 2-B on the bench here I'm starting to see 2nd tier issues that were not immediately apparent. In this example, the lathed/machined tuning shaft is slightly bent! What could have caused that without causing other significant physical damage to the radio? It's like finding a bent shaft inside a three layer cake!
I noticed the tuning knob has some slight but noticeable up and down and side to side play when rapidly tuning from low to high on a band - some wobble, not concentric. Then I noticed the same wobble in the shaft itself.
This isn't purely cosmetic-get-used-to-it damage. I now suspect the shaft wobble and resulting plus/minus dial string tension, however small, might be the cause of several brief dial slippages when tuning across a band.
what are the chances of finding a parts unit with a tuning shaft to spare? And I'd rather take a beating than restring the dial.
Comments, advice?
Dan
WB4GRA
|
Re: white line on 7 line knobs
I have found whiteout as used for typing or writing on paper to work very well
KL7AM
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----- Original Message ----- From: "Karl du Roi, DK7AL" <dk7al@...> To: "DRAKE-RADIO" < [email protected]> Sent: Sunday, May 7, 2023 5:05:05 AM Subject: Re: [DRAKE-RADIO] white line on 7 line knobs For such refurbish tasks I have simply taken some colour tins from Revell M5 or SM301 (white, not shiny) from the nearest hobby shop dealing with plastic models. The varnish can be applied into the recess of the knobs as described earlier in this subject. Best regards. Karl, DK7AL On 07.05.23 14:09, Steve Wedge, W1ES/4 via groups.io wrote: Another thing to consider is that if you clean the knobs in an ultrasonic cleaner, the paint will be gone when you¡¯re done.
I¡¯ve been using the putty stick to bring the lines and dots back but am considering going back to paint. Paint is the only way for 2 Line knobs.
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail for iOS
On Sat, May 6, 2023 at 22:52, Evan via groups.io <[k9sqg@...](mailto:On Sat, May 6, 2023 at 22:52, Evan via groups.io <<a href=)> wrote:
Jerry,
Sounds like you are making good progress.
As to the knobs, one of the antique radio vendors sells a white "putty stick" which one can rub onto/into the indicator lines on the knobs. After rubbing in, the excess can be wiped off with a cloth. For the perfectionist, white paint can be used to repaint the pointers. Sometimes just soaking in soap water and light brushing can restore the brightness but rubbing too hard can remove the paint.
73,
Evan, K9SQG
-----Original Message-----
From: jerry-KF6VB <jerry@...>
To: [email protected]
Sent: Sat, May 6, 2023 10:06 pm
Subject: [DRAKE-RADIO] TR7 Filters and Knobs
So today a care package arrived from Noble Radio. A 450Hz CW filter. A
true work of art. I did not delay in installing it. Had to do some
cleanup on the filter card; somebody had done a messy remove of its
original filters - all except the standard 2.3kHz SSB filter. Possibly
my Ebay seller. After all, why sell an INOP rig full of expensive
separately-saleable filters?
It works great. Single-signal CW reception.
While I was in there, I did the mod that lets the carrier control work
with SSB. It's just one wire tacked to two
terminals on the mode switch.
I also fixed the loose coax terminal I mentioned earlier. It turned
out that the "clip" part had come undone. Now
it's nice & tight.
Then I did something purely cosmetic: pulled off all the knobs and
treated them to an ultrasonic cleaner bath.
Except for the Mode switch and the Aux Program switch. Those don't seem
to have setscrews. How do they come off?
The white paint inside some of the pointer knobs - white paint inside
a groove - is a bit discolored and perished.
I may want to redo it.
- Jerry, KF6VB
|
Re: Drake 2-B Tuning Shaft Bent???
This may help. With a close look the bend may be apparent even in a fixed photo:
 Dan WB4GRA
toggle quoted message
Show quoted text
On May 7, 2023, at 11:38 AM, Dan <pitfit@...> wrote:
?As I continue to evaluate the 2-B on the bench here I'm starting to see 2nd tier issues that were not immediately apparent. In this example, the lathed/machined tuning shaft is slightly bent! What could have caused that without causing other significant physical damage to the radio? It's like finding a bent shaft inside a three layer cake!
I noticed the tuning knob has some slight but noticeable up and down and side to side play when rapidly tuning from low to high on a band - some wobble, not concentric. Then I noticed the same wobble in the shaft itself.
This isn't purely cosmetic-get-used-to-it damage. I now suspect the shaft wobble and resulting plus/minus dial string tension, however small, might be the cause of several brief dial slippages when tuning across a band.
what are the chances of finding a parts unit with a tuning shaft to spare? And I'd rather take a beating than restring the dial.
Comments, advice?
Dan
WB4GRA
|
Drake 2-B Tuning Shaft Bent???
As I continue to evaluate the 2-B on the bench here I'm starting to see 2nd tier issues that were not immediately apparent. In this example, the lathed/machined tuning shaft is slightly bent! What could have caused that without causing other significant physical damage to the radio? It's like finding a bent shaft inside a three layer cake!
I noticed the tuning knob has some slight but noticeable up and down and side to side play when rapidly tuning from low to high on a band - some wobble, not concentric. Then I noticed the same wobble in the shaft itself.
This isn't purely cosmetic-get-used-to-it damage. I now suspect the shaft wobble and resulting plus/minus dial string tension, however small, might be the cause of several brief dial slippages when tuning across a band.
what are the chances of finding a parts unit with a tuning shaft to spare? And I'd rather take a beating than restring the dial.
Comments, advice?
Dan
WB4GRA
|
Re: TR7 Filters and Knobs
I didn't put the metal VFO skirt in the bath. I cleaned it with isopropyl
alcohol and Q-tips. It came out fine; I was worried that the IPA would
take off the paint, but it didn't. The metal disks came out fine.
The VFO skirt had some sort of yellow schmutz on it.
My bath had a few drops of Dawn Ultra.
This ultrasonic cleaner isn't very strong. It's a Harbor Freight unit.
It will only time to 4 minutes, and it takes maybe 10 shots of that to
clean anything. I've been thinking of retiring it in favor of something
with good reviews on Amazon. There's still a little bit of dirt on the knobs.
I'll hit them with Q-tips and IPA.
- Jerry
|
Re: R-4C wire with no end stop
Peter, here is an educated guess as I do not have an R-4C in front of me.
Is the "wire" stiff and springy? If yes, it might have been used to provide a ground path for the metal part of the switch shaft. This would prevent coupling between two wafers of the switch that could lead to "filter blow-by." It is possible the "wire" was never put into the correct position during production.
Maybe someone else knows the real reason for the "wire."
Bob K9JU
On Saturday, May 6, 2023 at 09:18:52 AM EDT, Peter Ravn via groups.io <fasan5@...> wrote:
On the back of the print on the MODE/FILTER switch in my R-4C there is a 3 cm wire with no end stop. It is soldered onto the shield of the coax cable, and the solder looks original. Any idea what it is supposed to do? Serial number 18xxx.
Thanks.
Peter OZ8CTH
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Re: white line on 7 line knobs
FWIW I have used a water soluble acryllic paint stick, color: arctic white, to refurbish the white lines on the knobs for Drake TXany, Collins R390A, and various Icom gear.? Available at artist/craft supply stores.?
Clean knob, push paint into groove for white line, gently wipe with damp cloth parallel to the line to get a nice sharp line on the knob.
Above technique has worked great for me.
- 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 Sunday, May 7, 2023 at 07:05:20 AM MDT, Karl du Roi, DK7AL <dk7al@...> wrote:
For such refurbish tasks I have simply taken some colour tins from Revell M5 or SM301 (white, not shiny) from the nearest hobby shop dealing with plastic models. The varnish can be applied into the recess of the knobs as described earlier in this subject. Best regards. Karl, DK7AL On 07.05.23 14:09, Steve Wedge, W1ES/4 via groups.io wrote: > Another thing to consider is that if you clean the knobs in an ultrasonic cleaner, the paint will be gone when you¡¯re done. > > I¡¯ve been using the putty stick to bring the lines and dots back but am considering going back to paint. Paint is the only way for 2 Line knobs. > > Steve Wedge, W1ES/4 > > Time flies like an arrow. Fruit flies like a banana. > > Sent from Proton Mail for iOS > > On Sat, May 6, 2023 at 22:52, Evan via groups.io <[k9sqg@...](mailto:On Sat, May 6, 2023 at 22:52, Evan via groups.io <<a href=)> wrote: > >> Jerry, >> >> Sounds like you are making good progress. >> >> As to the knobs, one of the antique radio vendors sells a white "putty stick" which one can rub onto/into the indicator lines on the knobs. After rubbing in, the excess can be wiped off with a cloth. For the perfectionist, white paint can be used to repaint the pointers. Sometimes just soaking in soap water and light brushing can restore the brightness but rubbing too hard can remove the paint. >> >> 73, >> >> Evan, K9SQG >> >> -----Original Message----- >> From: jerry-KF6VB < jerry@...> >> To: [email protected]>> Sent: Sat, May 6, 2023 10:06 pm >> Subject: [DRAKE-RADIO] TR7 Filters and Knobs >> >> So today a care package arrived from Noble Radio. A 450Hz CW filter. A >> true work of art. I did not delay in installing it. Had to do some >> cleanup on the filter card; somebody had done a messy remove of its >> original filters - all except the standard 2.3kHz SSB filter. Possibly >> my Ebay seller. After all, why sell an INOP rig full of expensive >> separately-saleable filters? >> >> It works great. Single-signal CW reception. >> >> While I was in there, I did the mod that lets the carrier control work >> with SSB. It's just one wire tacked to two >> terminals on the mode switch. >> >> I also fixed the loose coax terminal I mentioned earlier. It turned >> out that the "clip" part had come undone. Now >> it's nice & tight. >> >> Then I did something purely cosmetic: pulled off all the knobs and >> treated them to an ultrasonic cleaner bath. >> Except for the Mode switch and the Aux Program switch. Those don't seem >> to have setscrews. How do they come off? >> >> The white paint inside some of the pointer knobs - white paint inside >> a groove - is a bit discolored and perished. >> I may want to redo it. >> >> - Jerry, KF6VB >> >> >
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