This is the Best Mods for Johnson Ranger Upgrade

[n8fvj]

In another post of Johnson Mods that had two pages of relies, this is the agreed by others best upgrade including expert DMOD approval. This post sorts thru and condenses the other previous post modifications for easy to follow instructions. The 12AU7 cathode and 1614 cathode capacitor recommendation is a bit high, IMO 47uF is plenty for 100Hz response. I also added some audiophile quality changes at end of article not mentioned by others.

I found this on AMfone posted in 2015 by member Tim WA1HnyLR.
Link: https://amfone.net/Amforum/index.php?topic=38167.0

'Although in past modifications  the stock audio gets bulldozed and a much higher performance resistance coupled circuit is used the limiting factor is the stock modulation transformer. By changing a number of circuit component values as well as omitting various capacitors that kill the high audio frequency response, very favorable results can be had. As with all modification that I have published ALL OF THEM MUST BE DONE IN ORDER TO GET THE RESULTS!.

Do not omit any steps in the following changes to the Ranger modulator. Unwanted ultrasonic oscillations may result if all of the procedures are not followed !

Let us begin at the beginning.

* R17 1Meg Microphonium grid resistor, Change to 3.3 Meg ohms . This is necessary for using a D-104 or other piezo-electric microphonium. (Note- per DMOD 3.3 meg ohm is preferred, not 10-15 meg ohm as mentioned).

* Replace C50A ( cathode bypass cap with a 25-100Mfd 10 volt min electrolytic cap.

* Change C51 (0.1MFD decoulpling cap) with a 10-20MFD 450 Volt electrolytic cap.

* Change C52 500 pF audio coupling cap to a .005-.01Mfd 600V tubular capacitor ( Orange drop type or equiv.)  

* Remove C53 (200 Pf Mica cap)  

* Remove C 56(470Pf cap from pin 6 of V 7-b to ground).

The modifications so far are pretty straight forward. It was found that the method of application of negative feedback in the original Johnson design could not be made to provide enough negative feedback to flatten out the low frequency response curve below 120Hz. The method of introducing the negative feedback point had to be changed. Rather than apply the feedback to the grid of V8 (12AU7)   application has been moved to feed the cathode of V7-B (12AX7)  second audio stage.

DO THE FOLLOWING:

* Replace C50-B with a value similar with that used for C 50-A  (25-50MFD @10VDC min. ) The negative end of the cathode bypass cap DOES NOT GO TO CHASSIS GROUND.  

* Place a 330 ohm 1/2 watt resistor is placed in series with the negative (-) end of the cap to ground. Negative feedback is introduced at the juncture of the cap and the resistor.

* Connect a 18-22K 1/2 watt resistor from the tertiary negative feedback winding to the juncture of the 330 ohm resitor and the - end of the cathode bypass capacitor(C 50-B).

* Place a 1MFD 100 volt min. non electrolytic cap (orange drop or equiv) in parallel (across) the tertiary negative feedback winding of T2 (modulation transformer). This step is important. Without the parallel cap there will be ultrasonic audio instabilities. This method of introducing negative audio feedback if far more effective.

Back to the rest of the audio section:

* Measure  C57 (.02MFD) audio coupling cap for leakage. If there is ANY leakage , replace cap with anything from a.01-.05 MFD 600V cap ( Orange drop  or equiv)

* Change R27 (150 K  grid resistor) with a 470K-680K 1/2 watt resistor. Being that in the original schematic one end of the resistor went to the tertiary negative feedback winding. Being that the negative feedback winding is feeding the cathode of  V7-B the end of the grid resistor now is connected from grid of V8 to ground.  

* Change C59-A (15MFD cathode bypass) is replaced with a 25-100 Mfd 25 VDC min. electrolytic cap.

* Change R28( 820 ohm 1/2 watt resistor) with a 680 ohm 1-2watt resistor. The higher dissipation rating improves reliability.

* Remove C60(.005 cap)  across secondary of T-3 audio driver transformer)

* Replace with a 10-12K 1 watt resistor. This is a swamping resistor. This step must not be omitted.

At this point the speech amplifier mods are completed. Now on to the modulator itself. Dynamic stabilization of both screen and bias voltages is important!  

* Replace C59-B with a 100-300Mfd 50 volt electrolytic cap.

* After setting modulator idle current between 70-80 M a measure the bias voltage. Place a zener diode or combination of zener diodes in series with each other from the center tap of the secondary of T3 (driver transformer to ground. This will stabilize  the bias voltage.  (Note- not for 1954 Ranger 1614 with cathode bias 200 ohm resistor).

* Place a 10-20MFD 450 volt cap in parallel with C71(.1MFD mod screen bypass cap).

The following are capacitor removals:

C69-.02MFD-C66-C67-C68-C 83 all.002@1.6Kv Disc ceramic caps.  

The following caps to be changed are in the RF section:

* C47 & C48 (.002 Mfd @1.6Kv disc ) Replace with 470 Pf-.001 MFD @ 3Kv disc ceramic caps. These are bypass caps at base of rf plate choke.

* Change C46  (.002 MFD screen bypass) with a 470-500Pf 1Kv disc ceramic cap.          

At this point you have completed  all of the transmitter modification pertaining to the modulator and modulated stage  The last phase of modification is the power supply.


HOME STRETCH ITEMS

 The power supplies need attention. The  bias supply must be solid-stated. Use 2-1kv diodes to take place of the 6AL5 (V 13).

* Replace C90-A & B  with a 100-200MFD 150 V electrolytic..  

* Replace C78(30  MFD 450 V  LV supply filter cap) with am 100-200Mfd 450V electrolytic cap. If the Ranger is going to be operated strictly as a low power exciter, the HV filter cap (C77-10MFD@700VDC ) may be replaced with a 100-200MFD 450V electrolytic.

You may want to use the Ranger with a high quality audio chain which requires line level input. Simply install an appropriate connector. A RCA connector or a 1/4 phone jack one jack on convenient location on rear of chassis. Run a length of shielded audio cable from the line level input jack to across the audio gain pot ( R21)'.

Audiophile quality mods (my N8FVJ suggestion):

Change 12AU7 (tube V8) to 6CG7. Rewire filament at socket. 12AU7 resistors and capacitors are same for 6CG7. Better 6CG7 are Raytheon USA manufacture or CBS Hytron. RCA black plate with top getter are ok. This change makes an audio quality improvement with better linearity and lower distortion.

Use polypropylene capacitors at 12AX7 C52 and C57. I say use .02uF on both for best low and high frequency response. Any cap larger than .02uF will degrade high frequency response by 3dB.

Best 12AX7 is JJ E83CC frame grid tube. NOS does not compare. This tube also will improve the audio response with better clarity. Tubestore has best price.

Better tubes and coupling capacitors from certain manufactures makes an audio quality improvement and my background of modifying stereo tube amps over 30 years is a contributing factor.

Use transorb (zener) 24 volt @ 5 watt in series for 312 volts regulated voltage for the 1614 tubes screens. Reset the resistor R35 tap at about 330 volts before connecting the transorbs. The audio will be improved with lower distortion.

Note: although the mods lower the audio frequency response to 100Hz or lower in the preamp and driver stages, the modulation transformer limits the audio to about 300Hz with about 70% modulation at best. In AMfone transmitter section my post 'Johnson Ranger Audio Mod' details installation of a modulation transformer providing 100 Hz audio at 100% modulation.

[Pete, WA2CWA]

Before we move forward with this thread:

Have you personally implemented any these changes to a Johnson Ranger?

Do you have data to prove that your changes make a difference in the performance of the Ranger? If you have data, please post it.

What is your technical background so readers might have a feeling of confidence in reading all of these additional Johnson Ranger part and circuit changes?

[DMOD]

...

Audiophile quality mods:

Change 12AU7 (tube V8) to 6CG7. Rewire filament at socket. 12AU7 resistors and capacitors are same for 6CG7. Better 6CG7 are Raytheon USA manufacture or CBS Hytron. RCA black plate with top getter are ok. This change makes an audio quality improvement with better linearity and lower distortion.

I am no expert but I can read schematics and I do have experience with both audio and RF circuits.

This suggestion is totally unnecessary; no need to rewire for a 6CG7 since there is no real advantage over a 12AU7A.

Use polypropylene capacitors at 12AX7 C52 and C57. I say use .02uF on both for best low and high frequency response. Any cap larger than .02uF will degrade high frequency response by 3dB.

If you don't change R27 to a 470k you will lose all low frequency response and still sound like Donald Duck.

Use polypropylene 47uF @ minimum of 50 volts for C59A. Higher capacitance is not needed for 100hz response.

There is no need to use a $15.00+ poly cap when a $1.00 Nichicon electrolytic cap works just fine and has the exact same circuit operation and effect.

Best 12AX7 is JJ E83CC frame grid tube. NOS does not compare. This tube also will improve the audio response with better clarity. Tubestore has best price.

That is a decent tube but in my opinion Tubestore has inflated prices; can you say, "Robber Barons?"

Use transorb (zener) 24 volt @ 5 watt in series for 312 volts regulated voltage for the 1614 tubes screens. Reset the resistor R35 tap at about 330 volts before connecting the transorbs. The audio will be improved with lower distortion.

You do realize that setting the R35 tap affects the 6146 screen voltage via the 6AQ5 clamp tube V6, which you seem to have ignored. Set the R35 tap so the 6146 screen voltage (or V6 Pin 5) is no more than 185V at CW Keydown and when properly tuned. Tune up (loading) affects the screen voltage; use a dummy load when adjusting.

A transorb and a zener are two different components and are to be used in different applications. You would need 13 of the 24V zeners to regulate; what value of series resistor (ohmic value and power rating) would you be using?

Tap off the 550V HV and use my screen regulator circuit (fits nicely on a 2X2" vectorboard) to regulate mod screen voltage. The Mosfet pass transistor will dissipate less than 2 watts.  


I don't agree with Zenering the bias voltage. When 1614 mod tubes are replaced slight bias adjustments are often needed and one zener voltage is not a "one-size-fits-all" solution.

Remove C90A,B and replace with one 33uF 160V electrolytic. Do the same for C59B and replace with one 33uF 160V electrolytic.

[n8fvj]

...

Audiophile quality mods:

Change 12AU7 (tube V8) to 6CG7. Rewire filament at socket. 12AU7 resistors and capacitors are same for 6CG7. Better 6CG7 are Raytheon USA manufacture or CBS Hytron. RCA black plate with top getter are ok. This change makes an audio quality improvement with better linearity and lower distortion.

I am no expert but I can read schematics and I do have experience with both audio and RF circuits.

This suggestion is totally unnecessary; no need to rewire for a 6CG7 since there is no real advantage over a 12AU7A.

Use polypropylene capacitors at 12AX7 C52 and C57. I say use .02uF on both for best low and high frequency response. Any cap larger than .02uF will degrade high frequency response by 3dB.

If you don't change R27 to a 470k you will lose all low frequency response and still sound like Donald Duck.

Use polypropylene 47uF @ minimum of 50 volts for C59A. Higher capacitance is not needed for 100hz response.

There is no need to use a $15.00+ poly cap when a $1.00 Nichicon electrolytic cap works just fine and has the exact same circuit operation and effect.

Best 12AX7 is JJ E83CC frame grid tube. NOS does not compare. This tube also will improve the audio response with better clarity. Tubestore has best price.

That is a decent tube but in my opinion Tubestore has inflated prices; can you say, "Robber Barons?"

Use transorb (zener) 24 volt @ 5 watt in series for 312 volts regulated voltage for the 1614 tubes screens. Reset the resistor R35 tap at about 330 volts before connecting the transorbs. The audio will be improved with lower distortion.

You do realize that setting the R35 tap affects the 6146 screen voltage via the 6AQ5 clamp tube V6, which you seem to have ignored. Set the R35 tap so the 6146 screen voltage (or V6 Pin 5) is no more than 185V at CW Keydown and when properly tuned. Tune up (loading) affects the screen voltage; use a dummy load when adjusting.

A transorb and a zener are two different components and are to be used in different applications. You would need 13 of the 24V zeners to regulate; what value of series resistor (ohmic value and power rating) would you be using?

Tap off the 550V HV and use my screen regulator circuit (fits nicely on a 2X2" vectorboard) to regulate mod screen voltage. The Mosfet pass transistor will dissipate less than 2 watts.  


I don't agree with Zenering the bias voltage. When 1614 mod tubes are replaced slight bias adjustments are often needed and one zener voltage is not a "one-size-fits-all" solution.

Remove C90A,B and replace with one 33uF 160V electrolytic. Do the same for C59B and replace with one 33uF 160V electrolytic.

You and I will never agree and that is because I have 30+ years audiophile tube experience and you have none. On a weak signal the increased audio quality would not be heard, but on strong signals yes. The 12AU7 is about the worst audio tube ever made and I am sure you do not know that. In fact, it was so bad Collins Radio the first user complained and how poor the 12AU7 was and RCA made a more linear 5814 to replace the 12AU7. But, you are saying a 12AU7 is just fine. Not.

In another post you state to use ceramic capacitors in the audio chain as the Ranger coupling capacitors. I shown you in oscilloscope pictures how non-linear the ceramic capacitors are (horrid) and how linear the polypropylene are capacitors perform. Readers take a look at DMOD ceramic cap suggestion here vs my polypropylene capacitor here and judge for yourself: https://www.diyaudioprojects.com/mirror/members.aol.com/sbench102/caps.html

The non regulated 1614 screen resistors are reported to have higher distortion vs regulated. In fact, you regulate your Ranger screens with a J-FET transistor as stated in another post, but state useless here.

The R27 resistor is already documented to change to 470K. Why your post?

The transorb are a high performance zener and far less cost. You JFET is fine, but has an electronic device that can fail unlike zener. I state regulate at 312 volts vs the Ranger 300 volt bogy setting that varies greatly with the modulation. I stated to raise voltage to 330 then attach the zeners. R35 tap goes to the 1614 screens thru switch SW4B. Your post makes no sense.

As for C59, an electrolytic capacitor is not the same as a poly cap. Way different performance in cathode circuits. Fact is only a few Rangers use a cathode resistor at modulator tubes in beginning of 1954, rest use fixed bias. Your knowledge is limited. Stay away from audiophile quality audio discussions.

Stop arguing with me just for the sake of argument.

Simply, you could careless how the audio sounds in your Ranger.

BTW- The JJ 12AX7 is only $33 at the tube store. They are not 'robber barons' as you state. Amazon is $67.

[n8fvj]

Before we move forward with this thread:

Have you personally implemented any these changes to a Johnson Ranger?

Do you have data to prove that your changes make a difference in the performance of the Ranger? If you have data, please post it.

What is your technical background so readers might have a feeling of confidence in reading all of these additional Johnson Ranger part and circuit changes?

Pete, the author of the mods is not me and is clearly stated with a link at beginning of the post. DMOD who has a lot of Ranger mod experience approved all these mods in another post with the exception of first 12AX7 grid resistor change from 10-15 meg ohm to 3.3 meg ohm as explained in this post. I am somewhat sure you approve and will not question any post from DMOD vs me that you always challenge with a few exceptions.

[DMOD]

I was addressing your personal "Audiophile quality mods"  Comments in which you are the author.

BTW, I used N-channel Mosfets, not J-Fets, in the screen regulator.

From here on, I'll let Pete address any further comments.

[n8fvj]

I was addressing your personal "Audiophile quality mods"  Comments in which you are the author.

BTW, I used N-channel Mosfets, not J-Fets, in the screen regulator.

From here on, I'll let Pete address any further comments.

I know you were dismissing my audiophile quality mods. Not necessary for the Ranger to work, but does provide better audio despite your comments of not performing. Pete did not question the previous post in Johnson Viking Ranger Mods that is same as this post. I just pulled that post from the two pages of replys to make it easier to read.

Glad you are 'dropping' it.

[Pete, WA2CWA]

N8FVJ: I will ask this one more time:

Have you personally implemented any of your changes to a Johnson Ranger?

Do you have data to prove that your changes make a difference in the performance of the Ranger? If you have data, please post it.

What is your technical background so readers might have a feeling of confidence in reading all of these additional Johnson Ranger part and circuit changes?

It's not good  idea to post untested or non-verified modifications or changes to any amateur equipment to the radio amateur community. In the case of the "HLR" Ranger modifications, they have been around for a good number of years and have been implemented and tested in many Rangers. Modified "HLR" Rangers can generally be found on the air regularly on 40, 75, and 160 meters all over the U.S.

I've reviewed your FCC license information and noticed that you let you license expire in 2004 and then reinstated the same license call letters as a vanity call in 2015.
So, in those years of active operating, how long have you been on the AM mode and what equipment have you been using to operate in the AM mode?

[n8fvj]

N8FVJ: I will ask this one more time:

Have you personally implemented any of your changes to a Johnson Ranger?

Do you have data to prove that your changes make a difference in the performance of the Ranger? If you have data, please post it.

What is your technical background so readers might have a feeling of confidence in reading all of these additional Johnson Ranger part and circuit changes?

It's not good  idea to post untested or non-verified modifications or changes to any amateur equipment to the radio amateur community. In the case of the "HLR" Ranger modifications, they have been around for a good number of years and have been implemented and tested in many Rangers. Modified "HLR" Rangers can generally be found on the air regularly on 40, 75, and 160 meters all over the U.S.

I've reviewed your FCC license information and noticed that you let you license expire in 2004 and then reinstated the same license call letters as a vanity call in 2015.
So, in those years of active operating, how long have you been on the AM mode and what equipment have you been using to operate in the AM mode?

First, I did not post untested or non-verified Ranger mods as you state. AMfone accepted these mods already in 2015. But, you wanting to know me better is ok and some history. And, I understand being a moderator is not easy. I am not as skilled as W8JI or DMOD here. My skills are good except I do not have a complete Lab to test every parameter in the Ranger mods. Some mods such as coupling capacitor value increases are well known to provide lower frequency response in audio circuits. Larger value capacitors are well known to reduce AC ripple in circuits. You do not need a Lab to know this. W8JI shows increased low frequency response on the Ranger first 12AX7 plate 500 pF cap and other audio caps here: http://www.w8ji.com/Johnson%20audio%20mods.htm

My Michigan location AM station in early 2017 to 2021 was a Ranger and Collins 51J-4. I sold the station in MI when I moved to FL.

I lived in NYC from 2003 to 2015 and a HF transmit antenna was not an option at the high rise building where I lived thus the Ham license lapse. However my foremost hobby is SWLing and performed that in NYC. I SWLed since 1962, been a Ham since 1985. I own a Yaesu FTDX-10, but have not used it for last 6 months. However, I do own it. Moving to FL I found a 75 meter Southeast AM net that is great and I do plan to get on this AM net. I want as close to commercial AM broadcast station quality audio and I do know how to achieve it with a Ranger to about 6Kz. AM Broadcast station audio is about 10 kHz, but 6 kHz is ok with me. More fun using vintage AM equipment vs modern SSB on the air. Modern SSB is almost like using a cell phone to me. No challenge but I am not a DXer. I do think I belong on this forum.

Anyways, I owned a modified Johnson Ranger with about same mods as posted here I bought in early 2017 but did not perform the zener mod and feedback loop change to the 12AX7. I did not also use the 1614 cathode resistor capacitor change as the Ranger I owned did not have the early 1614 cathode resistor. All other mods I performed did closely or exactly match the mods beyond the zener and feedback change listed here. However, Pete you act like these are my personal mods and they are NOT. Pete, the mods listed here were already accepted by this forum in 2015, yet you act like they are new in 2023. You did not have an issue with the mods in 2015.
 
All mods have been performed in Rangers at one time or another per an internet search with little variation in this post except none other than this post and post in 2015 have the revised feedback loop and none with the zener mod. DMOD approved the feedback mod and a similar 1614 screen regulation mod in his Ranger so ask him if they are viable.

Why am I putting so much effort into a Ranger when large legal limit transmitters are available? Because I own a legal limit HF amp that will make a large signal.
 
Anyways, I did install the Heyboer larger mod transformer never performed by another Ham posted in the Transmitter section here. I am not making up the timeline as you can also see the Heyboer mod posted at the Antique Radio forum by jimbenedict (author with same name as my N8FVJ call) 3-1/2 years ago here: https://www.antiqueradios.com/forums/viewtopic.php?f=5&t=377362&sid=955c50d1a2f664f7db2af3364e8839c9

The Ranger with the larger Heyboer mod transformer performed in 2017 was reported on the DX-60 net in MI where I lived to have outstanding audio. This was due to in part the audiophile mods I listed in this post here and the larger Heyboer mod transformer. Plus my background of 30 years improving stereo tube amps is a contributing factor. The audio upgrades cannot be measured with Lab equipment, only a human ear can decipher the upgrades as I performed. The larger mod transformer was engineered by Heyboer Transformer, not me. If you also do not trust Heyboer Transformer post it here. Heyboer is the première Ham radio transformer builder in the world since 1950. A stock Ranger could never achieve 100 Hz 100% modulation. I measured the modulation with a 100Hz tone and verified 100+ percent modulation here:

[KD1SH]

Speaking of the DX-60 net, here's my WA1QIX modified DX-60 at 20hz and 100% modulation:

[n8fvj]

I have not heard back from Pete WA2CWA for a few days with his concerns and my reply. Guess my post is approved.

[n8fvj]

Speaking of the DX-60 net, here's my WA1QIX modified DX-60 at 20hz and 100% modulation:

Your modified DX-60 is making me think I spent too much on my Johnson Ranger even if the DX-60 needs an external VFO. Can you list the DX-60 modifications for 20Hz audio?

[KD1SH]

http://amfone.net/Amforum/index.php?topic=26603.0

Speaking of the DX-60 net, here's my WA1QIX modified DX-60 at 20hz and 100% modulation:

Your modified DX-60 is making me think I spent too much on my Johnson Ranger even if the DX-60 needs an external VFO. Can you list the DX-60 modifications for 20Hz audio?

[n8fvj]

Thanks KD1SH.