Re: TR7 Service Kit - Extender Boards Needed
Mike, FYI in Drake parlance this is known as the "Jumper Board" and is described as such in the TR7 service manual. 73 -Jim NU0C On Thu, 16 Mar 2023 11:07:38 -0400 "Mike Bryce" <prosolar@...> wrote: I did make a ¡®bridge¡¯ board to connect the cards necessary to run the transceiver without the DR board.
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Re: Sourcing T4Xany cathode and screen grid resistors
I don¡¯t have the answer to that. I did, however, throw out some carbon resistors recently (and I¡¯m in an ongoing process with my stock, which dates back decades) that were grossly out of spec, even for 10 or 20% parts. Those were probably from the 1930s, judging by their appearance.?
My stock came back to me from my friend Brent, W1IA (SK), who had received them from me in 2006, when I moved. I got them from a co-worker in the 1980s, and they belonged to his dad, who was a TV repairman, so most of the parts are at least 37 years old. Other parts had been added over the years by Brent and me.?
Most of the parts look more ¡°modern¡± and most of those are still good, so far.?
Not all of the resistors in our Drakes have gone out of tolerance. The parts are affected by time, use, storage environment and other factors.?
I tend to only start measuring components when something is not working right or if I need to adjust a pot or cap to its extreme value. One could go crazy worrying about the parts, so we have to invest a certain amount of ¡°faith¡± that the parts inside are ¡°close enough¡±.?
73,
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail for iOS
On Thu, Mar 16, 2023 at 12:26, Bill Leonard N0CU < billincolo73@...> wrote: Steve, I agree. This is more of a temporary fix for me. Once I get everything working I will go back and replace them with new parts. What I don't remember is what is the drift profile of carbon comp resistors. Does continue indefinitely at a fairly constant rate or does it level off. If it is the latter, then I am not sure whether replacing them is necessary.
On Thu, Mar 16, 2023 at 9:56?AM Steve Wedge, W1ES/4 via <w1es= [email protected]> wrote: The problem with that with respect to the cathode and screen resistors is that the out of tolerance parts will continue to drift out of tolerance. It¡¯s best to use new replacements of the original value.
73,
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail for iOS
On Thu, Mar 16, 2023 at 11:09 AM, Bill Leonard N0CU < billincolo73@...> wrote: Since I have several boxes full of resistors, I have simply been measuring the starting resistance and calculating what parallel resistance is needed. I trimmed the meter shunt to 1% and matched the cathode and grid resistor to 1-2%.
On Wed, Mar 15, 2023 at 8:58?PM Doug Crompton WA3DSP < wa3dsp@...> wrote: 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
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Re: Sourcing T4Xany cathode and screen grid resistors
Steve, I agree. This is more of a temporary fix for me. Once I get everything working I will go back and replace them with new parts. What I don't remember?is what is the drift profile of carbon comp resistors. Does continue indefinitely at a fairly?constant rate or does it level off. If it is the latter, then I am not sure whether replacing them is necessary.
On Thu, Mar 16, 2023 at 9:56?AM Steve Wedge, W1ES/4 via <w1es= [email protected]> wrote: The problem with that with respect to the cathode and screen resistors is that the out of tolerance parts will continue to drift out of tolerance. It¡¯s best to use new replacements of the original value.?
73,
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail for iOS
On Thu, Mar 16, 2023 at 11:09 AM, Bill Leonard N0CU < billincolo73@...> wrote: Since I have several boxes full of resistors, I have simply been measuring the starting resistance and calculating what parallel resistance is needed. I trimmed the meter shunt to 1% and matched the cathode and grid resistor to 1-2%.
On Wed, Mar 15, 2023 at 8:58?PM Doug Crompton WA3DSP < wa3dsp@...> wrote: 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
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Re: DRAKE MN-2000 Ceramic wafer replacement/repair for Antenna Selector Switch help?
This is a standard sized wafer that has a quirky difference from a standard 2 pole 5 position wafer. The Common for one side is in the middle instead of at one end.
You get around this by drilling out the rivet on the common and of the terminal that is in the desired position for that common on a new standard wafer and repositioning it in the proper position. You replace the rivet with an 0-80 brass screw and nut. I use brass so that I can solder the nut permanently after tightening.
I have done this dozens of times with great results.
Gary
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On Mar 13, 2023, at 10:16 AM, Peter A <christinepeterarsenault@...> wrote:
and
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Re: TR7 Service Kit - Extender Boards Needed
Those are the boards that I have and they work very well.?
73,
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail for iOS
On Thu, Mar 16, 2023 at 11:07 AM, Mike Bryce < prosolar@...> wrote: Hi, gang!
Several years ago, I came out with a set of extender boards for the TR7. They consisted of a board set for each specific card. One for the Audio/IF, another for the power supply/osc board, etc.?
They weren¡¯t big sellers, and thus I never made the set for the bottom cards. However, although not shown in the photos here, I did make a ¡®bridge¡¯ board to connect the cards necessary to run the transceiver without the DR board.
I will have to check the shop, but I think I have some of the bare/blank pcbs for the bridge board, maybe for some of the other ones, too.
These are expensive to make as they are large double sided pcbs to begin with and they are extremely labor intensive to assemble.?
Why is that? You ask?
Due to supply issues, sometimes you can get the 15 pin connector, so you need to use three 5 pin connectors. Oops, you can¡¯t get the five pin connectors, then you need four 3 pin connectors and a 2 pin connector. They all mate and match, so that¡¯s not problem. It¡¯s the jigsaw way you need to assemble the boards. It would really be nice to simply order the correct part.
If there is enough interest, (10 people for min pcb run) I can have another short run made.
That would be for 7 board, what is shown below and the bridge board.
NO connectors, $50 +$10 shipping priority mail.
73
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Re: Need help with the planetary drive on T-4XC
That is also an advantage.?
Slightly OT, general purpose grease on the PTO bearings is what Drake used and its use also helped keep those 10 balls in place during reassembly.?
73,
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail for iOS
On Thu, Mar 16, 2023 at 11:32 AM, Bill Leonard N0CU < billincolo73@...> wrote: Steve & Joe, I was suspecting that oiling the bearings could cause slipping. However, both of the veriers I have were packed with a thick grease. So, I will follow Steve's recommendation and try some wheel bearing grease, if for no other reason, to make the assembly of the bearings possible. Something is needed to hold the bearings in place while the shaft is rotated around to each of the four positions.
On Thu, Mar 16, 2023 at 6:26?AM Steve Wedge, W1ES/4 via <w1es= [email protected]> wrote: 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
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Re: Sourcing T4Xany cathode and screen grid resistors
The problem with that with respect to the cathode and screen resistors is that the out of tolerance parts will continue to drift out of tolerance. It¡¯s best to use new replacements of the original value.?
73,
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail for iOS
On Thu, Mar 16, 2023 at 11:09 AM, Bill Leonard N0CU < billincolo73@...> wrote: Since I have several boxes full of resistors, I have simply been measuring the starting resistance and calculating what parallel resistance is needed. I trimmed the meter shunt to 1% and matched the cathode and grid resistor to 1-2%.
On Wed, Mar 15, 2023 at 8:58?PM Doug Crompton WA3DSP < wa3dsp@...> wrote: 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
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Re: TR7 Service Kit - Extender Boards Needed
dave and the group,
finding .156 connectors are easy¡ªdigikey and mouser have them by the millions!
However, you need to know the series like KK or KW, KS, the pitch. Do you want locking tabs? What size pins? Male? Female? Surface mount or through hole? Let¡¯s not forget straight pins or 90? pins!
Go to
search for .156 connectors
That will drop down a menu list.
Select series type
Then mounting type
number of pin
and so on.
If you don¡¯t see what you need, simply back up and re-search.
Download the data sheets, too.?
good luck!
Mike, WB8VGE
SunLight Energy Systems
The Heathkit Shop
.com/
J e e p
o|||||||o?
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Show quoted text
On Mar 16, 2023, at 11:41 AM, Dave Cutts via < g4faw@...> wrote:
Can anybody tell me where to get the .156 connectors from please? Thanks Dave G4FAW
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Re: TR7 Service Kit - Extender Boards Needed
Can anybody tell me where to get the .156 connectors from please? Thanks Dave G4FAW
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Re: Need help with the planetary drive on T-4XC
Steve & Joe, I was suspecting that oiling the bearings could cause slipping. However, both of the veriers I have were packed with a thick grease. So, I will follow Steve's recommendation and try some wheel bearing grease, if for no?other reason, to make the assembly of the bearings possible. Something is needed to hold the bearings in place while the shaft is rotated around to each of the four positions.
On Thu, Mar 16, 2023 at 6:26?AM Steve Wedge, W1ES/4 via <w1es= [email protected]> wrote: 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
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Re: Need help with the planetary drive on T-4XC
Gary, That is my plan. I am going to stop at Harbor Freight today and pick up an 8 in C clamp. I have been thinking about how the assembly should go. My?theory?of the moment is that the preload pressure on the spring sets the rotation tension (similar to the set screw on the PTO shaft) and the positioning of the large brass shaft aligns the bearing housing to be vertical. Not knowing what the preload should be, or anyway to measure it, it is probably going to be an iterative procedure. I will let you know how it goes.
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
Since I have several boxes full of resistors, I have simply been measuring the starting resistance and calculating what parallel resistance is needed. I trimmed the meter shunt to 1% and matched the cathode and grid resistor to 1-2%.?
On Wed, Mar 15, 2023 at 8:58?PM Doug Crompton WA3DSP < wa3dsp@...> wrote: 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
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Re: TR7 Service Kit - Extender Boards Needed
Hi, gang!
Several years ago, I came out with a set of extender boards for the TR7. They consisted of a board set for each specific card. One for the Audio/IF, another for the power supply/osc board, etc.?
They weren¡¯t big sellers, and thus I never made the set for the bottom cards. However, although not shown in the photos here, I did make a ¡®bridge¡¯ board to connect the cards necessary to run the transceiver without the DR board.
I will have to check the shop, but I think I have some of the bare/blank pcbs for the bridge board, maybe for some of the other ones, too.
These are expensive to make as they are large double sided pcbs to begin with and they are extremely labor intensive to assemble.?
Why is that? You ask?
Due to supply issues, sometimes you can get the 15 pin connector, so you need to use three 5 pin connectors. Oops, you can¡¯t get the five pin connectors, then you need four 3 pin connectors and a 2 pin connector. They all mate and match, so that¡¯s not problem. It¡¯s the jigsaw way you need to assemble the boards. It would really be nice to simply order the correct part.
If there is enough interest, (10 people for min pcb run) I can have another short run made.
That would be for 7 board, what is shown below and the bridge board.
NO connectors, $50 +$10 shipping priority mail.
73
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Re: Sourcing T4Xany cathode and screen grid resistors
Why not just buy from Mouser or Digikey? Both located in the USA.
Better pricing and more variety available and an excellent on line
catalog, no minimum order.
73, Jim W7RY
On 3/16/2023 7:31 AM, Steve Wedge,
W1ES/4 via groups.io wrote:
Yes, these guys are great. I¡¯ve bought lots of
caps from them.?
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail for iOS
On Thu, Mar 16, 2023 at 1:57 AM, Doug Crompton WA3DSP <wa3dsp@...> wrote:
I often buy
parts from justradios.com - here is the resistor link -
Doug, WA3DSP
--
Thanks and 73, Jim W7RY
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Re: Sourcing T4Xany cathode and screen grid resistors
Yes, these guys are great. I¡¯ve bought lots of caps from them.?
Steve Wedge, W1ES/4
Time flies like an arrow. Fruit flies like a banana.
Sent from Proton Mail for iOS
On Thu, Mar 16, 2023 at 1:57 AM, Doug Crompton WA3DSP < wa3dsp@...> wrote: I often buy parts from justradios.com - here is the resistor link -
https://www.justradios.com/resistors.html
Doug, WA3DSP
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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
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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
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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
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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
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Jim Shorney
Doug Crompton WA3DSP