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.
By
Steve Wedge, W1ES/4
·
#70001
·
|
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
By
Doug Crompton WA3DSP
·
#70000
·
|
12BY7 substitute
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
By
Doug Crompton WA3DSP
·
#69999
·
|
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
By
Steve W7SJT
·
#69998
·
|
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
By
Doug Crompton WA3DSP
·
#69997
·
|
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
By
Joe WB9SBD <nss@...>
·
#69996
·
|
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
By
Gary WB6OGD
·
#69995
·
|
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
By
Gary WB6OGD
·
#69994
·
|
Re: Sourcing T4Xany cathode and screen grid resistors
Bravo my friend. 73, Bill AE8EA
By
william pinkava
·
#69993
·
|
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
By
Steve Wedge, W1ES/4
·
#69992
·
|
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
By
Bill Leonard N0CU
·
#69991
·
|
Re: Sourcing T4Xany cathode and screen grid resistors
Even at? 400ma (total) cathode current, those 15¦¸ cathode resistors (@200ma ea)? would only dissipate (I 2 R) about 0.6W Since no one (ever) operates a T4X key down at 400ma , 1W cathode resistors
By
Rick WA6III <myr748@...>
·
#69990
·
|
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
By
Bill Leonard N0CU
·
#69989
·
|
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 [Proton Mail](https://proton.me/) secure email.
By
Steve Wedge, W1ES/4
·
#69988
·
|
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
By
Steve W7SJT
·
#69987
·
|
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
By
JP Nery
·
#69986
·
|
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 "John B" <wb9fhl@...> wrote:
By
Jim Shorney
·
#69985
·
|
Re: TR7 Service Kit - Extender Boards Needed
Absolutely correct Peter. I have never manufactured the extenders. 73 -Jim NU0C "VE7PS" <ve7ps@...> wrote:
By
Jim Shorney
·
#69984
·
|
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
By
VE7PS
·
#69983
·
|
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
By
Gary WB6OGD
·
#69982
·
|