Re: Need help with the planetary drive on T-4XC
I use heavy wheel bearing?grease. ?It provides plenty of friction. I won¡¯t look up the brand, as the jar of this stuff is from the 1950¡¯s and has been a lifetime supply for both my dad and me.?
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail for iOS
On Wed, Mar 15, 2023 at 10:35 PM, Joe WB9SBD < nss@...> wrote:
and NEVER OIL THEM. oil them
and 90% chance they will not work any longer. They NEED
friction to function.
Joe WB9SBD
On 3/15/2023 9:32 PM, wb6ogd wrote:
Bill,
These are planetary drives.. the "bearings" are actually like
gears, THEY are what you need to pre-load.
Clamp it end to end to compress the spring a little, then tighten
the screws.
That is my idea anyway.. having never worked on a C-line vernier,
hi hi...
73,
Gary
WB6OGD
|
Re: Sourcing T4Xany cathode and screen grid resistors
I often buy parts from justradios.com - here is the resistor link -
https://www.justradios.com/resistors.html
Doug, WA3DSP
|
Curious if anyone has ever used either a 12DQ7 or 12BV7 in place of the 12BY7 in a T4XC?? I have to search through my thousands of tubes and while I will primarily be looking for a 12BY7 I was just wondering if the other two would work. Characteristics seems very similar, and of course pin out is the same.
?
Doug, WA3DSP
|
Re: Sourcing T4Xany cathode and screen grid resistors
Thanks for the practical, common sense application feedback guys.
For wattage it looks like I will stick with the original specs, maybe go 1 watt, and also not be overly focused on tighter value tolerance as long as the measured resistances are very close.
- Steve? W7SJT
"Always look for a positive solution then Improvise, Adapt, and Overcome" - adaptation of the U.S. Marine Corps motto "Every day is an opportunity to challenge the achievement of your dreams"
"Success is not final, failure is not fatal.? It is the courage to continue that counts."
-?Winston Churchill
On Wednesday, March 15, 2023 at 07:15:47 PM MDT, Steve Wedge, W1ES/4 via groups.io <w1es@...> wrote:
The fact that these 50-60 year old radios have continued running well on the parts that they were made from is a testament to their overall good design.?
Most of the problems appearing in these sets today are due to long-term ageing of the components.?
IMO, in most ¡ª but not all ¡ª situations, the original parts specs have served very well. When we replace an original part, most of us?will be long-gone before it will need replacement again.?
You won¡¯t go wrong replacing like with like.?
73,
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail for iOS
On Wed, Mar 15, 2023 at 20:45, Rick WA6III < myr748@...> wrote: Even at? 400ma (total) cathode current, those 15¦¸ cathode resistors (@200ma ea)? would only dissipate (I2R) about 0.6W
Since no one (ever) operates a T4X key down at 400ma , 1W cathode resistors would have more than enough headroom....
6JB6 screen current per tube would have to be over 120ma for the screen resistor to dissipate 1w.? Somehow I think the screen current is a fraction of 120.
Just looked on eBay and found 15¦¸, 68¦¸ 1% 1w film type resistors for something like $3 and free shipping.
"10 Pieces 1 Watt 1% metal film resistors Over 200 Various Value YOU CHOOSE"
And if you want higher power ......
"10Pcs 5W 5 Watt Metal Film Resistor ¡À1% 0.1 - 91 ¦¸ Ohm 0.1 R to 91 R 6*17MM"
Just do a search for the above text on eBay.
Cheers,
Rick
--
73/Rick
WA6III
*Every post is created using Linux
|
Re: Sourcing T4Xany cathode and screen grid resistors
There is NO reason these resistors need to be 1%. 5 or even 10% are fine and you can always select from a stash to match them if that is your thing. They don't even need to be exactly the specified resistance, as long as it is close and they are reasonably matched. Someone put 10 ohm 2W cathode resistors in my T4XC. That vaue would probably be more likely to be found. The only resistor that might benefit from being 1% is the 3.3 ohm meter shunt, but that is also a stretch given the accuracy of the meter itself.
--
Doug, WA3DSP
|
Re: Need help with the planetary drive on T-4XC
and NEVER OIL THEM.? oil them
and 90% chance they will not work any longer.? They NEED
friction to function.
Joe WB9SBD
On 3/15/2023 9:32 PM, wb6ogd wrote:
toggle quoted message
Show quoted text
Bill,
These are planetary drives..? the "bearings" are actually like
gears, THEY are what you need to pre-load.
Clamp it end to end to compress the spring a little, then tighten
the screws.
That is my idea anyway.. having never worked on a C-line vernier,
hi hi...
73,
Gary
WB6OGD
|
Re: Need help with the planetary drive on T-4XC
Bill,
These are planetary drives..? the "bearings" are actually like gears, THEY are what you need to pre-load.
Clamp it end to end to compress the spring a little, then tighten the screws.
That is my idea anyway.. having never worked on a C-line vernier, hi hi...
73,
Gary
WB6OGD
|
Re: Sourcing T4Xany cathode and screen grid resistors
I would stick to the Drake specs. too.
I know that the 1500 ohm 1/2 watt resistors that supply the B+ to the stages in the R-4 series work like fuses.
Put in a larger power one and possibly damage the attached series coil or other parts.?? Ask me how I know...
73,
Gary
WB6OGD
|
Re: Sourcing T4Xany cathode and screen grid resistors
Bravo my friend. ?73, Bill AE8EA
toggle quoted message
Show quoted text
On Mar 15, 2023, at 9:15 PM, Steve Wedge, W1ES/4 via groups.io <w1es@...> wrote:
? The fact that these 50-60 year old radios have continued running well on the parts that they were made from is a testament to their overall good design.?
Most of the problems appearing in these sets today are due to long-term ageing of the components.?
IMO, in most ¡ª but not all ¡ª situations, the original parts specs have served very well. When we replace an original part, most of us?will be long-gone before it will need replacement again.?
You won¡¯t go wrong replacing like with like.?
73,
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail for iOS
On Wed, Mar 15, 2023 at 20:45, Rick WA6III < myr748@...> wrote: Even at? 400ma (total) cathode current, those 15¦¸ cathode resistors (@200ma ea)? would only dissipate (I2R) about 0.6W
Since no one (ever) operates a T4X key down at 400ma , 1W cathode resistors would have more than enough headroom....
6JB6 screen current per tube would have to be over 120ma for the screen resistor to dissipate 1w.? Somehow I think the screen current is a fraction of 120.
Just looked on eBay and found 15¦¸, 68¦¸ 1% 1w film type resistors for something like $3 and free shipping.
"10 Pieces 1 Watt 1% metal film resistors Over 200 Various Value YOU CHOOSE"
And if you want higher power ......
"10Pcs 5W 5 Watt Metal Film Resistor ¡À1% 0.1 - 91 ¦¸ Ohm 0.1 R to 91 R 6*17MM"
Just do a search for the above text on eBay.
Cheers,
Rick
--
73/Rick
WA6III
*Every post is created using Linux
|
Re: Sourcing T4Xany cathode and screen grid resistors
The fact that these 50-60 year old radios have continued running well on the parts that they were made from is a testament to their overall good design.?
Most of the problems appearing in these sets today are due to long-term ageing of the components.?
IMO, in most ¡ª but not all ¡ª situations, the original parts specs have served very well. When we replace an original part, most of us?will be long-gone before it will need replacement again.?
You won¡¯t go wrong replacing like with like.?
73,
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail for iOS
On Wed, Mar 15, 2023 at 20:45, Rick WA6III < myr748@...> wrote: Even at? 400ma (total) cathode current, those 15¦¸ cathode resistors (@200ma ea)? would only dissipate (I2R) about 0.6W
Since no one (ever) operates a T4X key down at 400ma , 1W cathode resistors would have more than enough headroom....
6JB6 screen current per tube would have to be over 120ma for the screen resistor to dissipate 1w.? Somehow I think the screen current is a fraction of 120.
Just looked on eBay and found 15¦¸, 68¦¸ 1% 1w film type resistors for something like $3 and free shipping.
"10 Pieces 1 Watt 1% metal film resistors Over 200 Various Value YOU CHOOSE"
And if you want higher power ......
"10Pcs 5W 5 Watt Metal Film Resistor ¡À1% 0.1 - 91 ¦¸ Ohm 0.1 R to 91 R 6*17MM"
Just do a search for the above text on eBay.
Cheers,
Rick
--
73/Rick
WA6III
*Every post is created using Linux
|
Re: Need help with the planetary drive on T-4XC
Peter, It looks like those might work, however, I suspect that there is no way to use the red pointer with one. I am still hoping to find out how to put the one I have back together. Nothing is broken- I just can't figure out how to get the preload on the bearings. Thanks for your suggestion. I will keep your idea as Plan B.
On Wed, Mar 15, 2023 at 2:59?PM VE7PS < ve7ps@...> wrote: How about installing a Jackson Bros 6:1 ball drive on the sub-panel?? You could even use one of the more rare, dual speed ones, for very precise control.? I've used these on homebrew?VHF amps with great success.? I can't think of why it wouldn't work there as well.? The one Drake used was a very cheap version of the same thing. Bean counter influence, no doubt, as they were around back then.
73 Peter VE7PS
Now I see..? the C-line is different from my A and B lines!
If it does depend on pre-load like you say, you just need a big clamp..? and remove the final cage and tubes.
My biggest clam is not big enough but you get the idea.
Or, nobody says you really need a vernier.? My early T-4X and the up to the early R-4A rigs didn't have them.
I even watched a YouTube recently that the guy bragged about the nice fast adjustment on his early rig!
Just freeze the two shafts somehow, maybe JB Weld or squeezing them?
73,
Gary
WB6OGD
|
Re: Sourcing T4Xany cathode and screen grid resistors
Even at? 400ma (total) cathode current, those 15¦¸ cathode resistors (@200ma ea)? would only dissipate (I2R) about 0.6W
Since no one (ever) operates a T4X key down at 400ma , 1W cathode resistors would have more than enough headroom....
6JB6 screen current per tube would have to be over 120ma for the screen resistor to dissipate 1w.? Somehow I think the screen current is a fraction of 120.
Just looked on eBay and found 15¦¸, 68¦¸ 1% 1w film type resistors for something like $3 and free shipping.
"10 Pieces 1 Watt 1% metal film resistors Over 200 Various Value YOU CHOOSE"
And if you want higher power ......
"10Pcs 5W 5 Watt Metal Film Resistor ¡À1% 0.1 - 91 ¦¸ Ohm 0.1 R to 91 R 6*17MM"
Just do a search for the above text on eBay.
Cheers,
Rick
--
73/Rick
WA6III
*Every post is created using Linux
|
Re: Need help with the planetary drive on T-4XC
Gary, My Plan A is to use a clamp just as you suggested, even if I need to fabricate one. However, after playing around with the vernier today I am not sure how to assemble it so it has the required preload. My initial thought results in a preload on the shafts, but not the bearings.I must be missing something really basic because this is not a complicated part. Thanks for your help. I'll let you know how it turns?out. If I can't get it to work again, I like your idea of just not worrying about the vernier and directly couple the shafts.
Now I see..? the C-line is different from my A and B lines!
If it does depend on pre-load like you say, you just need a big clamp..? and remove the final cage and tubes.
My biggest clam is not big enough but you get the idea.
Or, nobody says you really need a vernier.? My early T-4X and the up to the early R-4A rigs didn't have them.
I even watched a YouTube recently that the guy bragged about the nice fast adjustment on his early rig!
Just freeze the two shafts somehow, maybe JB Weld or squeezing them?
73,
Gary
WB6OGD
|
Re: Sourcing T4Xany cathode and screen grid resistors
The screen resistors are 1/2 watt, as built.? This may help you.
Steve Wedge, W1ES/4
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
------- Original Message -------
On Wednesday, March 15th, 2023 at 7:04 PM, Steve Toth via groups.io <stoth47@...> wrote:
Maybe I'm just being too exacting about this, but I cannot seem to find any one supplier that has in stock both of the "oversized" precision sizes of cathode and screen grid resistors that have been discussed in previous threads.
Specifically:? 15 ohm, Film, 1%, 3 watt cathode resistors ? ? ? ? ? ? ? ? ? 68 ohm, Film, 1%, 2 watt screen grid resistors
I thought it would be easy, but after several hours checking Mouser, Digikey, Newark, etc. no one place seems to have both as "in stock".? And with the required shipping charges on small orders I'm just trying to find one place that has both items.
So, at what source are you guys finding both of these little gems? and what are the acceptable types, and part numbers?? Search parameters?
Maybe I'm just not searching on the correct items.
Thanks.
- Steve? W7SJT
"Always look for a positive solution then Improvise, Adapt, and Overcome" - adaptation of the U.S. Marine Corps motto "Every day is an opportunity to challenge the achievement of your dreams"
"Success is not final, failure is not fatal.? It is the courage to continue that counts."
-?Winston Churchill
?
|
Sourcing T4Xany cathode and screen grid resistors
Maybe I'm just being too exacting about this, but I cannot seem to find any one supplier that has in stock both of the "oversized" precision sizes of cathode and screen grid resistors that have been discussed in previous threads.
Specifically:? 15 ohm, Film, 1%, 3 watt cathode resistors ? ? ? ? ? ? ? ? ? 68 ohm, Film, 1%, 2 watt screen grid resistors
I thought it would be easy, but after several hours checking Mouser, Digikey, Newark, etc. no one place seems to have both as "in stock".? And with the required shipping charges on small orders I'm just trying to find one place that has both items.
So, at what source are you guys finding both of these little gems? and what are the acceptable types, and part numbers?? Search parameters?
Maybe I'm just not searching on the correct items.
Thanks.
- Steve? W7SJT
"Always look for a positive solution then Improvise, Adapt, and Overcome" - adaptation of the U.S. Marine Corps motto "Every day is an opportunity to challenge the achievement of your dreams"
"Success is not final, failure is not fatal.? It is the courage to continue that counts."
-?Winston Churchill
?
|
Re: TR7 Service Kit - Extender Boards Needed
Hi John, I have connectors on order for two sets of extenders.? They should arrive tomorrow.? It appears you can use a set right away and could be a way for me to test the first prototype set I make.? I have a few techs in the EU that have requested a set.? I would prefer to test out a set in the USA before shipping outside the country. Call or write if you like so we can make a deal. John WA1ESO? ? WA1ESO@...? ?401-624-4576
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Re: TR7 Service Kit - Extender Boards Needed
Bear in mind also that it is not difficult to power up individual boards "naked" on the workbench to do some basic troubleshooting. 73 -Jim NU0C On Wed, 15 Mar 2023 09:42:02 -0700 "John B" <wb9fhl@...> wrote: Thanks Dave.? I do plan to do a thorough mechanical cleaning before proceeding with troubleshooting board by board.? Just got to get it on the bench first.
73, John
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Re: TR7 Service Kit - Extender Boards Needed
Absolutely correct Peter. I have never manufactured the extenders. 73 -Jim NU0C On Wed, 15 Mar 2023 08:35:37 -0700 "VE7PS" <ve7ps@...> wrote: Mark:
Jim Shorney can check in later after work....but I do not believe he ever
made TR-7 extender cards to sell to others....or even for himself. That
link on Ron's page refers to extender card sets that were made and sold by
Bob, W7AVK. I met him at a PNWVHFS conference in Moses Lake about 10 years
ago and he had stopped making them at that time, though I believe he had a
few sets left then. Bob's e-mail address is on his QRZ site.
Mike made a pretty limited supply of his excellent boards. I have a set
and they are unique in that there is a separate SINGLE extender for each of
the TR-7 boards, unlike the ones Drake (and others) were (are?) offering.
Not sure what the current status of availability is.
73
Peter
VE7PS
On Wed, Mar 15, 2023 at 6:58?AM Mark - WB0IQK <mgilger@...> wrote:
John,
Have you checked with Jim Shorney? He makes the extender boards. Go to
Ron's web page here:
Drake Membervellia (wb4hfn.com)
<>
Mike Bryce, The Heathkit Shop, also has them. Look on page 14 of the
following link on Ron's website.
Microsoft Word - #62 DRAKE TECH EXCHANGE-2022.doc (wb4hfn.com)
<>
73's,
Mark, WB0IQK
|
Re: Need help with the planetary drive on T-4XC
How about installing a Jackson Bros 6:1 ball drive on the sub-panel?? You could even use one of the more rare, dual speed ones, for very precise control.? I've used these on homebrew?VHF amps with great success.? I can't think of why it wouldn't work there as well.? The one Drake used was a very cheap version of the same thing. Bean counter influence, no doubt, as they were around back then.
73 Peter VE7PS
Now I see..? the C-line is different from my A and B lines!
If it does depend on pre-load like you say, you just need a big clamp..? and remove the final cage and tubes.
My biggest clam is not big enough but you get the idea.
Or, nobody says you really need a vernier.? My early T-4X and the up to the early R-4A rigs didn't have them.
I even watched a YouTube recently that the guy bragged about the nice fast adjustment on his early rig!
Just freeze the two shafts somehow, maybe JB Weld or squeezing them?
73,
Gary
WB6OGD
|
Re: Need help with the planetary drive on T-4XC
Now I see..? the C-line is different from my A and B lines!
If it does depend on pre-load like you say, you just need a big clamp..? and remove the final cage and tubes.
My biggest clam is not big enough but you get the idea.
Or, nobody says you really need a vernier.? My early T-4X and the up to the early R-4A rigs didn't have them.
I even watched a YouTube recently that the guy bragged about the nice fast adjustment on his early rig!
Just freeze the two shafts somehow, maybe JB Weld or squeezing them?
73,
Gary
WB6OGD
|
Doug Crompton WA3DSP
Gary WB6OGD
Jim Shorney
