Odd Johnson Ranger

[n8fvj]

I received a Johnson Ranger today. Appears untouched in factory stock build. It does not have the keyer 12AU7 and missing the tube plate for the 6AL5 and 12AU7 on left front of chassis. No machine holes are on the chassis for the tube plate support. As if it was never there. Serial number 60600. Any ideas?

[KD1SH]

I have a Ranger 1 here, but I'm far from a Ranger expert. As far as I know, the earliest Ranger 1's didn't have what Johnson called their "differential keyer" at all; that came with later iterations. A very good Ranger reference, if you haven't see it:

https://www.frostburg.edu/personal/latta/ee/ranger/ranger.html

[n8fvj]

1954 Ranger tube line up does not include a 6AL5, 5763 or the 12AU7 keyer per this post. How does this transmitter make bias voltage?

[n8fvj]

I found 1954 schematic. The Ranger uses cathode bias on the 1614 tubes. This 1954 Johnson Ranger has about 30 less volts tube plate to cathode on the modulator tubes vs next year and later Rangers using a 6AL5 for 1614 tube bias voltage. What does the later Rangers 5763 tube perform vs this Ranger without the 5763 tube?

[n8fvj]

Some modulator considerations. This 1954 Ranger has cathode bias vs fixed bias. The cathode bias produces less power output vs later Ranger fixed bias and is also about 30 volts less modulator tube plate voltage to cathode vs later Rangers. The Ranger 1954 modulator looks to be about 30 watts output including transformer losses or not enough for 100% modulation in stock condition at full Ranger RF output. Later Rangers with fixed bias produce about 45 watts modulator output. Based upon 7027A tube specs, the screen voltage needs to be increased to about 380 volts. If increasing the screen voltage from 300 to 384 volts with zener regulation, a second resistor tap is needed. I would use an array of 24 volt 5 watt transorbs (zeners) to regulate the screens to keep the power up. The 384 volts must be directly wired thru switch SW4B vs shared with the 6AQ5 tube. The 6AQ5 clamper tube uses 300 volts that shares with the 1614 tube. 384 volts is not good idea on a 6AQ5 that is rated at 250 max volts. The new tube screen 384 volts should produce about 45 watts out with fresh tubes. If the tube plates operate at dull red glow at idle, reduce the screen to 360 volts. Another option is the 6550 tube data. At 500 volts with a 170 ohm vs stock 200 ohm cathode resistor the screen may stay at 300 volts. If this works, the zener will be reduced to 318 volts. I will verify the correct screen voltage and update this post using Sovtek 6L6WXT+ tubes.

The 1614 tubes would be way overtaxed at this higher screen volts or lower cathode resistance with the 25 watt rated plates. The tubes would be dissipating about 70 watts plate (two tubes) set up with 500 volts plate and 384 volts screen with the 200 ohm cathode resistor or same 70 watts for the 6550 set up at 300 volts screen. Although the 7027A tube would be great for this application they are very expensive and needs a socket pin out change.

I would use Sovtek 6L6WXT+ tubes with about 35 watts plate dissipation each that is close to same operating parameters as the 7027A tube or possibly a 6550 tube. 6L6WXT+ uses same 35 watt plate as the re-issue Tung Sol 7027A with a 35 watt plate. The Sovtek tubes are rated at 500 volts and the 1954 Ranger provides about 500 volts plate to cathode. There is a report on the internet the Sovtek 6L6WXT+ replaced 7027A tubes as used in an Ampeg guitar amp with 550 volts plate and 500 volts screen and has worked well for a few years. I will verify if the Sovtek 6L6WXT+ act like a 7027A tube or 6550 tube by measuring the plate current. The Sovtek 6L6WXT+ are $59 a pair new on ebay. The 6550 are about $150 a pair.

Power supply consideration. The 5R4 tube is rated at 250ma current. However into a choke at 250ma current the tube can supply 340ma current out the choke per power supply simulator PSU2 due to no rectifier peak current vs a capacitor input filter. No issue with the 5R4 tube.

The 1614 draw 60ma at idle and peak at 120ma (160ma in later Rangers) and the 6L6WXT+ draw 150ma at idle and peak at 190ma. Then the rest of tubes draw current, but the 1954 Ranger has same power transformer size as the 1955 and later Rangers with two more tubes and 160ma peak modulator current. The power transformer will be loaded heavier at idle, but capable of the higher 1614 160ma peak current it was designed to supply. The transformer will operate a little hotter, but should be good. The transformer HV is rated at 260ma continuous duty, should be ok at 50% duty cycle. If it fails, I will buy a Heyboer M6 lam heavy duty transformer capable of 1/3 higher HV current.

Note- I assume the Ranger tiny mod transformer can modulate about 100% at 400Hz with the Sovtek 6L6WXT+ tubes. In my application I will be using the Heyboer heavy duty modulator transformer that can take 3x the stock Ranger mod transformer current and produce 100Hz at 100% modulation.

[Pete, WA2CWA]

I found 1954 schematic. The Ranger uses cathode bias on the 1614s and also uses some of that cathode bias for other tubes. This 1954 Johnson Ranger has about 30 less volts tube plate to cathode on the modulator tubes vs next year and later Rangers. What does the later Rangers 5763 tube perform vs this Ranger without the 5763 tube?

The first Viking Ranger model was in production from 1954 to 1961. Latter part of 1954 Johnson issued a modification kit to add the Keyer/Bias hardware and circuitry to the Rangers already in the hands of customers. Rangers manufactured from that point on included the Keyer/Bias hardware and circuitry as part of the manufacturing process. They updated the schematic and manual to reflect this change. Johnson made some circuit changes to the Ranger going forward but the schematic was only reissued one more time before the product was discontinued.

The 5763 tube was never used in the original Ranger. It was added to the Ranger II model and mounted on the main chassis. It was the tagged in the schematic as the 6 meter multiplier. The Keyer/Bias hardware and circuitry addition was still mounted on the same plate as was used in the original Ranger.

All this information is documented in the various Ranger, Ranger II, and Keyer Modification manuals.

[n8fvj]

I found 1954 schematic. The Ranger uses cathode bias on the 1614s and also uses some of that cathode bias for other tubes. This 1954 Johnson Ranger has about 30 less volts tube plate to cathode on the modulator tubes vs next year and later Rangers. What does the later Rangers 5763 tube perform vs this Ranger without the 5763 tube?

The first Viking Ranger model was in production from 1954 to 1961. Latter part of 1954 Johnson issued a modification kit to add the Keyer/Bias hardware and circuitry to the Rangers already in the hands of customers. Rangers manufactured from that point on included the Keyer/Bias hardware and circuitry as part of the manufacturing process. They updated the schematic and manual to reflect this change. Johnson made some circuit changes to the Ranger going forward but the schematic was only reissued one more time before the product was discontinued.

The 5763 tube was never used in the original Ranger. It was added to the Ranger II model and mounted on the main chassis. It was the tagged in the schematic as the 6 meter multiplier. The Keyer/Bias hardware and circuitry addition was still mounted on the same plate as was used in the original Ranger.

All this information is documented in the various Ranger, Ranger II, and Keyer Modification manuals.

I believe 6AL5 fixed bias appeared in 1955.

[Pete, WA2CWA]

I found 1954 schematic. The Ranger uses cathode bias on the 1614s and also uses some of that cathode bias for other tubes. This 1954 Johnson Ranger has about 30 less volts tube plate to cathode on the modulator tubes vs next year and later Rangers. What does the later Rangers 5763 tube perform vs this Ranger without the 5763 tube?

The first Viking Ranger model was in production from 1954 to 1961. Latter part of 1954 Johnson issued a modification kit to add the Keyer/Bias hardware and circuitry to the Rangers already in the hands of customers. Rangers manufactured from that point on included the Keyer/Bias hardware and circuitry as part of the manufacturing process. They updated the schematic and manual to reflect this change. Johnson made some circuit changes to the Ranger going forward but the schematic was only reissued one more time before the product was discontinued.

The 5763 tube was never used in the original Ranger. It was added to the Ranger II model and mounted on the main chassis. It was the tagged in the schematic as the 6 meter multiplier. The Keyer/Bias hardware and circuitry addition was still mounted on the same plate as was used in the original Ranger.

All this information is documented in the various Ranger, Ranger II, and Keyer Modification manuals.

I believe 6AL5 fixed bias appeared in 1955.

    Attachment below: EF Johnson Viking Ranger schematic with 6AL5 and 12AU7 additions - NOTE THE DATE
2nd schematic is what was included in the Keyer Modification Kit

[n8fvj]

I found 1954 schematic. The Ranger uses cathode bias on the 1614s and also uses some of that cathode bias for other tubes. This 1954 Johnson Ranger has about 30 less volts tube plate to cathode on the modulator tubes vs next year and later Rangers. What does the later Rangers 5763 tube perform vs this Ranger without the 5763 tube?

The first Viking Ranger model was in production from 1954 to 1961. Latter part of 1954 Johnson issued a modification kit to add the Keyer/Bias hardware and circuitry to the Rangers already in the hands of customers. Rangers manufactured from that point on included the Keyer/Bias hardware and circuitry as part of the manufacturing process. They updated the schematic and manual to reflect this change. Johnson made some circuit changes to the Ranger going forward but the schematic was only reissued one more time before the product was discontinued.

The 5763 tube was never used in the original Ranger. It was added to the Ranger II model and mounted on the main chassis. It was the tagged in the schematic as the 6 meter multiplier. The Keyer/Bias hardware and circuitry addition was still mounted on the same plate as was used in the original Ranger.

All this information is documented in the various Ranger, Ranger II, and Keyer Modification manuals.

I believe 6AL5 fixed bias appeared in 1955.

    Attachment below: EF Johnson Viking Ranger schematic with 6AL5 and 12AU7 additions - NOTE THE DATE
2nd schematic is what was included in the Keyer Modification Kit

My 1954 Ranger has a 200 ohm cathode resistor for the 1614 tubes.

[Pete, WA2CWA]

I found 1954 schematic. The Ranger uses cathode bias on the 1614s and also uses some of that cathode bias for other tubes. This 1954 Johnson Ranger has about 30 less volts tube plate to cathode on the modulator tubes vs next year and later Rangers. What does the later Rangers 5763 tube perform vs this Ranger without the 5763 tube?

The first Viking Ranger model was in production from 1954 to 1961. Latter part of 1954 Johnson issued a modification kit to add the Keyer/Bias hardware and circuitry to the Rangers already in the hands of customers. Rangers manufactured from that point on included the Keyer/Bias hardware and circuitry as part of the manufacturing process. They updated the schematic and manual to reflect this change. Johnson made some circuit changes to the Ranger going forward but the schematic was only reissued one more time before the product was discontinued.

The 5763 tube was never used in the original Ranger. It was added to the Ranger II model and mounted on the main chassis. It was the tagged in the schematic as the 6 meter multiplier. The Keyer/Bias hardware and circuitry addition was still mounted on the same plate as was used in the original Ranger.

All this information is documented in the various Ranger, Ranger II, and Keyer Modification manuals.

I believe 6AL5 fixed bias appeared in 1955.

    Attachment below: EF Johnson Viking Ranger schematic with 6AL5 and 12AU7 additions - NOTE THE DATE
2nd schematic is what was included in the Keyer Modification Kit

My 1954 Ranger gas a 200 ohm cathode resistor for the 1614 tubes.

In your reply #3 above you stated why.

[n8fvj]

I believe 6AL5 fixed bias appeared in 1955.
[/quote]

I agree. The modulator power went up from 32 watts to 45 watts in 1955.

[Pete, WA2CWA]

I believe 6AL5 fixed bias appeared in 1955.

I agree. The modulator power went up from 32 watts to 45 watts in 1955.

You're quoting yourself and it's incorrect. Look at the schematic I posted. It first appeared in 1954, then 1955, then 1956, etc. until it was discontinued in 1961.

[n8fvj]

I believe 6AL5 fixed bias appeared in 1955.

I agree. The modulator power went up from 32 watts to 45 watts in 1955.

You're quoting yourself and it's incorrect. Look at the schematic I posted. It first appeared in 1954, then 1955, then 1956, etc. until it was discontinued in 1961.

Apparently a 1954 mid year change.

[MikeKE0ZUinkcmo]

Mine was an early version without the extra transformer taps for the bias circuitry.   It was a field retrofit radio, and it works well.    Unfortunately it had seen a rough life and had a lot of battle scars, so when it came time to get it running again I didn't concern myself with keeping it original and made many power supply mods to cut down on power consumption.   Stock, they were very good space heaters.

[KD1SH]

Some very nice Ranger mods; well documented, photographed, and executed. I'll keep those in mind should I ever revisit my Ranger.
I like the way you put the sticky cushion pads on the edges of the front panel, to protect it while doing the work. Great idea!
I love the D104 head mounted in the microphone boom!

[n8fvj]

Mine was an early version without the extra transformer taps for the bias circuitry.   It was a field retrofit radio, and it works well.    Unfortunately it had seen a rough life and had a lot of battle scars, so when it came time to get it running again I didn't concern myself with keeping it original and made many power supply mods to cut down on power consumption.   Stock, they were very good space heaters.

The modulator tubes run all the time. I was thinking a relay to remove 1614 screen voltage during standby. The screens would likely need a 100K resistor to ground to maintain zero voltage.
Edit- looks like 1614 tube screen voltage is removed in standby.

[ns7h]

I acquired an early Ranger (S/N 61675) that did not have any mods or the fixed bias/keying platform from original (kit built) and was not recapped except for the capacitor C57 in the modulator circuit (did not work on AM).  After full electrolytic and paper cap replacement (and the Chernobyl resistor), it worked as advertised.  I was confused at first with the different schematics for the Ranger evolution.  I found the correct one from this forum (Thanks).  I did do the D-Lab mod for PTT and the K2 version does turn off the modulator tubes in standby. 

My audio sounds very good though the REA monitor shows shy of 100% modulation.  Now I learn later versions may have increased modulation power.

Good read, thanks for the learning opportunity.