Tech Tip Johnson Ranger Ham Transmitter best choice & method replacing filter capacitors tune & test
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- Опубліковано 25 лют 2022
- I have repaired many Johnson transmitters over the years. The Ranger is by far my favorite to work on. These classics rank the same as Vintage Fender guitar amps. They have both withstanded the test of time. A little TLC, fresh filter caps and they will last another 40 years! I only use the best components when working on these jewels. This video will guide you thru the process and point out some time + money saving tips. If you have any questions, comment or e-mail me. Long live vintage tube equipment!
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Thanks so much Terry for getting an old transmitter back on the bench! Truly enjoy watching you bringing these beautiful radios back to life! Much more interesting to me than just another amplifier….,enjoy all your videos but these are special in my opinion! Thanks again!
I think the Hammered Ham wine needs to be a fixture in D-Lab videos. Just like the Cobbler, Snauzoramous, and Troll. Chock full of tips today Terry!
Thanks for the armature transmission
Thanks D-lab
Excellent video
I used F&T caps in my Johnson Viking Adventurer. Now I just have to solve the problem of why the grid voltage on the 6AG7 oscillator tube is 140 volts key down instead of it’s rated 200 volts key down.
Thanks for the Ham content Terry!
Well done Terry , as always. That Hammered Ham Vino looks good brother !!
Great information!!! Thanks for sharing!
Some excellent tips on replacing old E caps with proper new E caps! Don't use anyone else's "shortcuts".🔨🐷🍷
Useful video. Thanks.
Nice tip
Terry IS tha man!!!! Thanks bro
I was gonna ask why you didn't open up those caps in the cardboard tubes... but you did. But you didn't answer the relevant questions. What were the cap uF and voltage ratings, and what brand were they?
at a buffet, i personally sneak corndogs into the buffet so others can enjoy them. I hide 6 corndogs in my jacket pockets. it then, is a joy for me to see other patrons of the establishment eat my corndogs thinking they were part of the buffe
That power transformer is a monster, isn't it?
Yes, These old rigs were built to last several lifetimes
What is the formula to calculate these resistors and caps value? I need to replace some big old filter caps in a tape machine
Terry, love your videos and info, but the one thing that is hard for me to deal with, is pigtailling. I know you have to make a buck, but I just can't move past this. I'm sure when I had my communications business, my techs could have put out more repairs, but I wouldn't allow pigtailling. Just a matter of preference. HiHi
Is it just me or many of these old transmitters had bad function switches? Heathkit seemed to notorious for it in their DX-35/40/60 models.
It seems to me that it was usually due to arcing because the Hi-V B+ was switched on and off at the function switch. Eventually it could burn off a contact. That's why a lot of folks move the B+ to a relay that's switched by the function switch.
Terry...thanks for this video. I have sent you an email. 73 de Arnie W8DU
Hi Terry, thanks for the video. I know Fender used 220k balancing resistors on the filter totem pole, and I just serviced an ultra linear Super that has 100k 1 watt ones. You used 470k. How do you decide what is the correct value? Is there a correct value? Thanks
The value is calculated by the high voltage the resistors have to handle. Fenders may be around 450V whereas the Johnson is around 700V. So the resistor value has to be adjusted to dissipate without exceeding their wattage
Ahhh, nice, a ham radio video! I thought making guitar amp videos paid more. What happened?
D LAB, what do you mean by "dripping the plate"? and you want to ground the transmitter to the chassis of the receiver to prevent HUM?
Thats Dipping the plate, indicates that the final is tuned. I used a jumper for a temp ground connection. The receiver has a ground cable on the rear. I just did the front panel connection out of convenience.
@@d-labelectronics When you Tune a receiver and get it tuned its called Dipping the Plate?
When you tune a transmitter to the frequency the plate current dips
@@d-labelectronics Any reasons why the plate current dips when the transmitter is tuned to the receivers frequency? I'm not sure why the receivers plate current dips or what is causing the plate current to dip
I thought dripping plates were caused by grid leaks...uh, okay, I'll just let myself out ...
What would happen if you put the caps in series without the 470k resistors?
If you did that, then you cannot guarantee that the voltage at the inner junction will be half of the total voltage, as both of the caps have slightly (more or less) different characteristics. This can endanger both of the caps.
Putting those resistors in place (more or less) guarantees that the voltage in the center will be close to one-half of the total voltage across the two caps. They act as a lower parallel DC resistance than the inner resistances of the caps, and thus will tend to control the voltage at the center point. Their resistances are high in order to minimize the power that they dissipate and to minimize the effect that they have on the caps - keeping the ripple low across the total capacitance.
Yes Sir, correct
@@cjay2 What about the values of the two resistors themselves? In terms of tolerance? What if one is at the low end of tolerance and the other is at the high end?
Hi Terry - Two 22uf caps in series gives you one at 44uf, not 11uf, right? Trust but verify…..
In Parallel they add, In series they subtract but the voltage doubles