Johnson Ranger question

[wa3dsp]

I recently started working on a Johnson Ranger I that someone gave to me years ago and it has been sitting on the shelf. Not an expert on Johnson but I suspect there might be someone here that could answer this question.

My Ranger does not have the board mounted topside to the left of the VFO with the keyer and bias rectifier tubes. Was this an original ranger before that addition or did someone take it out for some reason? The 6L6 cathodes are raised from ground by two 100 ohm 1W resistors in series with the meter shunt. The center tap of the 6L6 grid driver transformer is grounded.

I don't know if there are taps on the power transformer for bias. I would like to modify this for negative bias on the 6L6 grids with the cathode grounded. I don't care much about the keyer as I do not intend to operate CW with the Ranger. It would be rather easy to use a small transformer to get the bias with a solid-state rectifier.

If this was factory is there a schematic out there for it without this board?

Has anyone made this change on an older Ranger?

Most everything else in the unit looks like the schematic. My goal is to fully upgrade/update the unit. Is there any reason why this (older) Ranger would not work as good as a newer one on AM considering it was updated?

73 Doug, WA3DSP

[Pete, WA2CWA]

My Ranger does not have the board mounted topside to the left of the VFO with the keyer and bias rectifier tubes. Was this an original ranger before that addition or did someone take it out for some reason?

The first Rangers did not come with the keyer mod add-on.

If this was factory is there a schematic out there for it without this board?

Yes, the schematic was re-issued three times.

Has anyone made this change on an older Ranger?

Probably many hams over the years after the first Rangers were introduced. They sold a keyer mod add-on kit.

Most everything else in the unit looks like the schematic. My goal is to fully upgrade/update the unit. Is there any reason why this (older) Ranger would not work as good as a newer one on AM considering it was updated.

No reason, as long as the tubes are good, resistors are in tolerance, capacitors aren't leaky or shorted, etc.

[kA5WHO]

I don't know if there are taps on the power transformer for bias. I would like to modify this for negative bias on the 6L6 grids with the cathode grounded. I don't care much about the keyer as I do not intend to operate CW with the Ranger. It would be rather easy to use a small transformer to get the bias with a solid-state rectifier

No taps on the original ranger for bias.
Dan W1ur did as you propose built his own bias supply.
 I run mine everyday just as is.

dale/ka5who

[KB2WIG]

D,

Free advice.

Don't do anything untill...
Get a digi camera and take loads 'o pics of the thing.
Get rid of the Chernobyl resistor and replace with a big motha. ( yeah, ya can google it)
Replace the 'lytics.
Ya don't want to start changing things untill you have it working like it was suposed to originally. I screwed around like this and ended up chasing things in a cyrkle.

klc

[wa3dsp]

Thanks for the replies. I see now that there were three versions of the Ranger. I did find the schematic at the BAMA site. It is listed under the Ranger directory as early.djvu.

I have culled the Internet and pulled all of the ER articles over the years on the Ranger and I will try to make some sense of all of it. There are, as could be expected, lots of differing opinions especially on the audio section and one could get carried away on making mods. I am not a hot-rod audio freak so possibly a more subtle approach to the audio section is where I will go.

I recently upgraded both a Multi Elmac A54 and AF67. I modified the AF67 to use a phase inverter taking out the unreliable driver transformer. The A54 used the phase inverter stock. Both have excellent audio with a D104. Since the Ranger is just a glorified AF67 there is no reason it could not sound the same with reasonable modifications. Maybe when I get it all done I can document it to further dilute the pool of Ranger mods!

Doug

[KM1H]

IOW you went from AB2 to AB1 mods with that change? Does it fully modulate the 6146?

Carl

[wa3dsp]

You were talking about the AF67 mod? If so the answer is yes, it fully modulates the 6146 with good audio. I do run at least 600 volts of plate voltage though which also appears on the modulator plates. I regulate the modulator screens to about 270 volts. I wouldn't recommend running this high a plate voltage without some mods though. I did quite a few on the AF67 including moving the metering off of the high voltage leads. I moved the shunts to the mod. cathodes and PA cathode to get the high voltage off of the meter and switch. Also some rewiring of the high voltage leads.

Doug

[W3NE]

I'm returning to my Ranger restoration after a long interruption. Mine does not have the time sequence keyer so I am going to use a small 6.3 V. transformer in reverse from the heater line to get 120 to 125 V (~160 V p-p) and use a solid state bridge rectifier in place of the 6AL5.

Most published audio mods recommend replacing the modulator driver transformer with a better one (Hammond 124E). Anybody have comments on that?

A real fuse holder has been installed and that ridiculous crystal socket replaced with a snap-in a-c connector. Also, where clearance is tight some of the solenoid RFI coils will be replaced with ferrite beads, although as W3GMS has pointed out, some extremes that were taken with filtering might not be necessary today.

Doug, drop in when you get time and we can compare notes.

Bob

  

[wa3dsp]

  I am doing very similar things to my Ranger. Mine was given to me many years ago and I just got the bug to get it going. Actually Bill, DGB got me going on it when he started talking about his Bandmaster. I have one but it is a crude rig and I want something a little more modern in the shack for AM. Maybe someday I will get back to it. My Ranger is the original pre Ranger 1 model.

I will be solid-state'ing both supplies in the Ranger. I also removed the crystal socket relay jack and installed a real fuse holder. I used the now unused 5V winding to buck the primary.

My unit for some reason was very dirty under the chassis so I am spending a great deal of time cleaning as I go along. Krud Cutter, available at Lowes is great for that. Also deoxit in some situations. I use a lot of q-tips and paper towels!

I will be adding the bias transformer but I don't think I will take the time to add the keyer. I really don't intend to ever use this rig on CW. I do want to change the 6L6's to grid bias rather than the cathode bias it has now. As far as audio mods. I am not sure. My Ranger looks like it was a kit and the audio section is kind of messy. I may strip it down completely and go to a phase inverter eliminating the driver transformer all together. I did that on my AF67 (same tube lineup) and it worked great.

What I have found is that a great deal of stuff can come out leaving considerable room for mods. I removed all the RFI filters and replaced them with ferrite beads. Also removed the small filter choke and moved the large (HV) choke to the transformer center tap and ground. I had seen this done in a mod and it looked like a good idea. I have all of the AC primary circuits rewired and once I get the power supply back together I will see how the voltages look. I will also probably regulate the low voltage supply with a MOSFET.

I also intend to add PTT. Someone did already in this Ranger in a messy way. I am going to do it a different way so I will rip all that out first. I also added a BNC connector right next to the SO239 on the back. I have a relay I will mount close to that area for antenna change over. It will also have a contact for RX muting and external  (amplifier) keying. Anothe relay will be mounted, probably topside for the other contact requirements. Both relays are 12V coils.

I had mentioned before in another post about finding the rubber and cloth covered wire being very brittle in the bandmaster. On the ranger the only area where that is a problem is the leads from the chokes and transformer. I did find that if you have to move or work on the leads heating them seems to help. I use a heat shrink heat gun and carefully heat the lead. While it is hot you can move it to where you want. It doesn't totally solve the problem as the wire returns to being brittle when it cools off but at least you can move it without destroying it. I also put heat shrink over the leads when I can.

I made a compilation of all of the ER articles on the Ranger into a PDF. The only one I don't have is the 1990 issue. I only go back to 96 here. If anyone wants it I can email it.

Doug