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Burt
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« on: March 29, 2014, 06:31:59 PM » |
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I have two, one works pretty good and someone put in some nice mods, linear keying, output to receiver antenna and receiver muting. The only issue is barely acceptable grid drive on 40-10 meters and grid tuning is barely responsive, add to that it takes one second for grid drive to be 2 ma and thus full power is delayed. Not an issue on AM, but an issue on CW. A 40 meter crystal is even worse.
The other Ranger has real issues with the 5R4 pulled the 6AX5 arcs as I slowly bring up the variac, if I insert a 5u4 then it is the 5u4 that arcs. Of course I immediately bring down the AC.
I am not in the class of AM knowledge that virtually everyone else is here. I have repaired a number of DX-40-60s
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W2VW
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« Reply #1 on: March 29, 2014, 06:49:40 PM » |
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Take a good look at the filter cap the 6AX5 looks into. If it's old it's time for a change.
Once rectifier tubes show stress they are most likely finished also.
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N2DTS
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« Reply #2 on: March 29, 2014, 09:27:24 PM » |
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Nice to work you today on the ranger Burt!
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Burt
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« Reply #3 on: March 30, 2014, 06:35:28 AM » |
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Nice to work you today on the ranger Burt!
You sounded like a broadcast station! |
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N2DTS
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« Reply #4 on: March 30, 2014, 02:19:13 PM » |
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Thanks, I hope that is a good thing...
I never had a ranger, so i have no diagram, but maybe your grid drive issue has something to do with the keying circuit.
Some transmitters used some sort of bias setup to grid block key a transmitter, and maybe some component is off or leaking, or something.
Most times, more grid drive is better for AM.
Looking at the scope, you did not seem to have a lot of positive modulation, which low grid drive will cause.
That is best seen on a scope, or on a pep watt meter, say 40 watts of carrier should give about 160 watts pep out at 95% neg modulation.
Its sometimes hard to see modulation in detail on weaker signals on my end though.
The rig seemed to be working ok.
Lots of guys use rangers, barefoot or into an amp, so you should get some response...
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VE3AJM
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« Reply #5 on: March 30, 2014, 02:39:08 PM » |
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But according to some on here, a stock Ranger would have 10% distortion which equates to putting out audio spurs +-20kc from the carrier frequency. And it wasn't designed as a stand alone transmitter. That transmitter is no good.  Al VE3AJM |
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W2VW
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« Reply #6 on: March 30, 2014, 04:57:49 PM » |
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But according to some on here, a stock Ranger would have 10% distortion which equates to putting out audio spurs +-20kc from the carrier frequency. And it wasn't designed as a stand alone transmitter. That transmitter is no good. Al VE3AJM Al, Every transmitter puts out spurs. It's just a question of how much weaker than the desired signal they are. A Ranger at full power has plenty of audio distortion. Much of it can be eliminated when full power output is not needed. A legal limit AM signal should have every advantage practical to eliminated unwanted bandwidth. 20 years ago it would not be so difficult to get this point across. What has changed? 73, Dave |
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Steve - K4HX
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« Reply #7 on: March 30, 2014, 05:17:59 PM » |
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I just asked for actual measurements. Some how that gets turned into "the Ranger is no good." Let's see how bad or good the Ranger actually is and forget the non-sequitor comments.
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VE3AJM
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« Reply #8 on: March 30, 2014, 05:52:33 PM » |
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Hey I understand the theory with transmitters and distortion with audio. I was having a bit of fun with OIK. I guess that's not OK...geez....Happy Sunday..  Al VE3AJM |
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Steve - K4HX
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« Reply #9 on: March 30, 2014, 05:58:32 PM » |
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I was having fun too. Don't sweat it. |
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W2VW
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« Reply #10 on: March 30, 2014, 06:21:46 PM » |
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I was NOT having fun. Seeing AM turn into plug and play is not my idea of fun.
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Steve - K4HX
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« Reply #11 on: March 30, 2014, 07:24:23 PM » |
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Eh, many AMers buy a DX-100 (place boat anchor X, modern transceiver here), plug it in and get on the air. Plug and play. Been that way since commercial rigs became popular.
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N2DTS
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« Reply #12 on: March 30, 2014, 07:49:13 PM » |
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If you are not blowing glass for your own tubes, you are just an a plug and play operator...
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K5IIA
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« Reply #13 on: March 30, 2014, 08:36:45 PM » |
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If you are not blowing glass for your own tubes, you are just an a plug and play operator...
https://www.youtube.com/watch?v=GAMRHcbE3g0looks easy |
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Be kind, for everyone you meet is fighting a hard battle.
73, Brandon K5iia
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W2VW
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« Reply #14 on: March 30, 2014, 09:07:35 PM » |
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If you are not blowing glass for your own tubes, you are just an a plug and play operator...
U use off the shelf glass? |
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Steve - K4HX
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« Reply #15 on: March 30, 2014, 09:14:09 PM » |
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I blew the glass out on a tube once. Does that count?
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W2VW
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« Reply #16 on: March 30, 2014, 09:30:10 PM » |
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Only if you learned something from it.
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Steve - K4HX
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« Reply #17 on: March 30, 2014, 10:03:54 PM » |
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Sure did. Pay attention to the plate current when messing with the antenna tuning. That and that I am a dumb !@&$.
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KA2DZT
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« Reply #18 on: March 30, 2014, 10:25:59 PM » |
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Hey I understand the theory with transmitters and distortion with audio. I was having a bit of fun with OIK. I guess that's not OK...geez....Happy Sunday.. Al VE3AJM Al, Kidding around and making funnies is only allowed on alternate Sundays, you're off by one. Next Sunday you'll be fine. Fred |
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Burt
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« Reply #19 on: March 30, 2014, 10:35:32 PM » |
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The "other Ranger" I have done more work on, it has real issues. The one I used to talk to N2DTS is pretty much OK
As I continue to examine it I have found the 10 uf filter capacitors are NOT connected to where they should be but to the drive control. For what reason I do not know. Add to that their is a power resistor connected to the drive control that has no reason for being there. I checked schematics for various versions of the Ranger and nothing comes close to the wacky way this is wired. I am at a loss as to what the goal was for the person that was working on this. The modulation bias resistor and filter capacitor is connected directly to the 5R4 instead of being after the filter choke. This is all more than strange.
Oh the auxiliary coupling switch had split in two.
It looks like it may be a life's work to get it running.
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K1JJ
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« Reply #20 on: March 30, 2014, 11:35:54 PM » |
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Since you have one Ranger that is working OK, pull them both out of the cabinets and put them side by side. Carefully compare the circuitry to see if there was tampering in the non-working one.
Once the non-working one is put back to stock, do the same thing - get out the VOM and start measuring and comparing voltages in suspected stages. Use the ohmmeter to check resistor values. A cap checker will verify the caps are good. (You may have to disconnect them to get a good reading at times)
You will find the problems.
T
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Use an "AM Courtesy Filter" to limit transmit audio bandwidth +-4.5 KHz, +-6.0 KHz or +-8.0 KHz when needed. Easily done in DSP.
Wise Words : "I'm as old as I've ever been... and I'm as young as I'll ever be."
There's nothing like an old dog.
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wa3dsp
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« Reply #21 on: March 31, 2014, 12:04:13 AM » |
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It sounds like someone really butchered that Ranger. The drive control is a weak spot on Rangers. It is a 4 Watt pot and typically has more than 4 Watts dissipated through it. Often they open. I used a FET and a much smaller pot in my mods. It very smoothly controls grid drive and eliminates 4 watts of wasted heat. If you like fixing stuff then it is a nice challenge. If not then maybe it would be better to leave it alone. I have some good photos and descriptions of my Ranger mods. You could pick and choose what you wanted to do. The FET mod for the driver would be high on the list as well as getting the high and low voltage supplies back in order. Any original or old electrolytics should be trashed. You can go to much higher value and much physically smaller replacement parts. If you go solid-state you can use the 5V filament to buck the primary and reduce the voltage. I also got rid of the "Chernobyl" resistor and regulated the low voltage supply. http://www.crompton.com/hamradio/JohnsonRanger/RangerRestoration.html |
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Burt
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« Reply #22 on: April 03, 2014, 10:19:52 PM » |
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It sounds like someone really butchered that Ranger. The drive control is a weak spot on Rangers. It is a 4 Watt pot and typically has more than 4 Watts dissipated through it. Often they open. I used a FET and a much smaller pot in my mods. It very smoothly controls grid drive and eliminates 4 watts of wasted heat. http://www.crompton.com/hamradio/JohnsonRanger/RangerRestoration.htmlWith the bandswitch broken on my Ranger, is there a way around that? |
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flintstone mop
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« Reply #23 on: April 04, 2014, 07:28:37 PM » |
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It sounds like someone really butchered that Ranger. The drive control is a weak spot on Rangers. It is a 4 Watt pot and typically has more than 4 Watts dissipated through it. Often they open. I used a FET and a much smaller pot in my mods. It very smoothly controls grid drive and eliminates 4 watts of wasted heat. http://www.crompton.com/hamradio/JohnsonRanger/RangerRestoration.htmlWith the bandswitch broken on my Ranger, is there a way around that? Are you trying to get two good working Rangers ? You might find a parts unit on eBay or eHam or QTH.com Bandswitch arced out? Or ceramic cracked? Are you going to run barefoot on 40 or 20? Or drive a linear? It would be nice to get your sched for some QSO time. Fred |
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Fred KC4MOP
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Burt
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« Reply #24 on: April 05, 2014, 10:00:53 AM » |
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With the bandswitch broken on my Ranger, is there a way around that?
Are you trying to get two good working Rangers ? You might find a parts unit on eBay or eHam or QTH.com Bandswitch arced out? Or ceramic cracked? Are you going to run barefoot on 40 or 20? Or drive a linear? It would be nice to get your sched for some QSO time. Fred The ceramic is cracked. I have one working, I would like to get the other working. I can drive a linear. |
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