Ranger solid-state rectifiers

#367

Any Ranger owners out there who have replaced the rectifier tubes with silicon diodes?? If so, did you use dropping resistors to get the voltage back in the original range and if so, what resistance values did you use?

?

Please - I just want to know the answer to that and don't need responses as to why that's a terrible idea.? I know what the voltage drop across the tubes should be and know how to size the resistors, but the question is: what did YOU find to be good?? Thanks.

?

73, K8AC

#368

Hello

?? What WE do, in our Ranger overhaul/rebuild process is: build a rectifier network into a gutted 6AX5, ( so the result will plug into the OEM LV rectifier socket) AND we add a solid state +300V buss regulator into the system so we don't care that the resulting LV B+ is a few volts higher than OEM.

? That is what WE do.

?? From our perspective, the under-chassis heat in a Ranger from that HV dropping resistor/bleeder/ chassis heater and other dropping resistors deserves to go away in as careful a manner as possible, so adding more heat seems , to us, unnecessary. ( YMMV).

Thank You !!!

Ashley

?

Thank You

Kiss-Electronics

Ms Ashley Hall

183 N 5th PL.

Cornelius, Oregon

97113

?

W7DUZ

?

On Thursday, January 30, 2025 at 03:46:45 PM PST, Floyd - K8AC via groups.io <floydsense@...> wrote:

Any Ranger owners out there who have replaced the rectifier tubes with silicon diodes?? If so, did you use dropping resistors to get the voltage back in the original range and if so, what resistance values did you use?

?

Please - I just want to know the answer to that and don't need responses as to why that's a terrible idea.? I know what the voltage drop across the tubes should be and know how to size the resistors, but the question is: what did YOU find to be good?? Thanks.

?

73, K8AC

#369

Ashley . . .

On Fri, 31 Jan 2025 00:16:20 +0000 (UTC), "Ashley Hall via groups.io"
<Ashley40@...> wrote:

  What WE do, in our Ranger overhaul/rebuild process is: build a rectifier network into a gutted 6AX5, ( so the result will plug into the OEM LV rectifier socket) AND we add a solid state +300V buss regulator into the system so we don't care that the resulting LV B+ is a few volts higher than OEM.If you care to do so, could you attach a drawing of what you do for both of
these changes? I changed the settings for picture attachments to a higher
resolution. We don't have a files storage area in this free group since it was
formed after some changes were made to the free groups. 

Or, you can upload the files in this other group we manage, which I formed
before those changes happened to new free groups. 

/g/Vintage-Amateur-Radio-Restoration

We DO have file storage there, and it's not a heavily-used group. This comes
under vintage radio restoration so it's not out of line with the purpose of our
other group. Maybe do both?

Donald KX8K


----------------------------------------------------
Some ham radio groups you may be interested in:
/g/ICOM   /g/Ham-Antennas
/g/HamRadioHelp    /g/Baofeng
/g/CHIRP  

#372

Thanks, Ashley.? That's another option that I ran across recently and I'll look at that more closely.? I think I have all the components to try it.? Even with the added heat from a dropping resistor, the overall heat reduction from doing away with the tubes should make a big difference.? For now, I'm running with a 120mm muffin fan on top of the cabinet and that does a pretty good job of keeping things cool.? Do you retain the 5R4 for the high voltage rectifier???

?

73, Floyd

#373

Floyd Hello

??? TY for the kind words

We retain the 5R4 for two reasons: 1), The additional RF power output achieved with the increase in HV is negligible, and the HV increase puts a strain on HV components, 2)? the danger of high inrush AC primary currents associated with solid state HV rectifier circuits. An inrush current limiter circuit might? negate that possibility.?

?? What WE do, is add a +300V solid state regulated buss module, re-work the VFO/XTAL switch wiring to the Ranger wiring version 2 ( Johnson Keyer, Modulator bias circuit). We re-work the modulator bias circuit to allow for adjustable modulator bias.

? ? If the Ranger did not show up with the sub-chassis installed, we fabricate one. This chassis supports 1) Johnson OEM keyer, 2) Adjustable modulator bias circuit potentiometer.

?? The OEM 6AX5 is removed, its innards removed, some 1N4007 diodes added. This allows the operator, if desired, to use either the solid state re-worked 6AX5 OR the OEM 6AX5 vacuum tube.? No circuit changes necessary.

?? For Ranger wiring version 1( No Keyer or separate modulator bias circuit, no separate modulator bias winding on the power transformer), the sub-panel also supports a small 6VAC /split primary transformer which, when reversed, supplies the modulator bias voltage via a small encapsulated bridge rectifier, a couple of filter capacitors and a 10K miniature potentiometer.?

?? This bias circuit re-work allows that under-chassis HV heater/bleeder/divider resistor to be removed. ( Bye Bye all that heat).

Modulator idle IP is adjusted with the Bias Adjust Potentiometer. ( Book Idle IP is 70ma, we lower that slightly to 55ma).

? ? The OEM PTT circuit goes bye-bye, replaced with a solid state relay driver module, powered by the 6.3V heater circuit. ( Bye Bye more under-chassis heat and the associated power transformer loading) This module lives on the chassis, in the site of the OEM Johnson Logo Placard.

? ? The drive potentiometer is replaced with a solid state module. The VFO gas regulator tube and the associated heater resistor is replaced with a solid state +150VDC regulator circuit.

? ?? VFO oscillator tube socket is replaced with a mil-grade ceramic socket. Old silver mica band-set capacitors are replaced with modern 1% silver mica's. VFO ground circuit is improved. VFO shroud is modified to allow for easy removal in the unlikely event the VFO oscillator tube needs replacing or other VFO servicing is required.

? ?? HV filter circuit consists of (2) 100uf/450V electrolytics,in series, paralleled with (2) 150K 4w resistors.?

? ? LV bleeder function is accomplished via the solid state Drive, VFO solid state regulator and the +300V solid state buss regulator.

? ?? Power transformer loading is substantially reduced, under chassis heat is substantially reduced, VFO internal heat is substantially reduced ( the Johnson VFO becomes much more stable),?

? ? The single point OEM RF grounding scheme also goes bye-bye. RF grounding is a "multiple point" grounding. Keyer chirp goes away.?

? ? None of these fiddly-bits affect the RF power output, modulation % or quality. These modifications are all control related. Our initial goal was to reduce under-chassis component ( AKA bleeder resistors) generated heat, thereby reducing power transformer load.

?? YMMV.

Thank You for letting me post this sorta long ramble. We do not claim to be engineers, and we don't get into debates about the merits ( or lack of) these modifications. We do not modify OEM RF or modulator circuitry. We essentially gut the Ranger, clean the chassis and rebuild.

?? From our POV, the Ranger is a sweet, single 6146, low output aesthetically pleasing, easy to use AM/ CW transmitter. We do not attempt to " put lipstick on a pig", rather we try to re-work the Ranger into bit more robust, longer lasting and a pleasure to use transmitter.

?? We also re-work the 6146 output components, but that is another story.

Ashley

? ? ??

? ??

Thanks, Ashley.? That's another option that I ran across recently and I'll look at that more closely.? I think I have all the components to try it.? Even with the added heat from a dropping resistor, the overall heat reduction from doing away with the tubes should make a big difference.? For now, I'm running with a 120mm muffin fan on top of the cabinet and that does a pretty good job of keeping things cool.? Do you retain the 5R4 for the high voltage rectifier???

?

73, Floyd

?

Thank You

Kiss-Electronics

Ms Ashley Hall

183 N 5th PL.

Cornelius, Oregon

97113

?

W7DUZ

?

On Friday, January 31, 2025 at 05:16:37 AM PST, Floyd - K8AC via groups.io <floydsense@...> wrote:

Thanks, Ashley.? That's another option that I ran across recently and I'll look at that more closely.? I think I have all the components to try it.? Even with the added heat from a dropping resistor, the overall heat reduction from doing away with the tubes should make a big difference.? For now, I'm running with a 120mm muffin fan on top of the cabinet and that does a pretty good job of keeping things cool.? Do you retain the 5R4 for the high voltage rectifier???

?

73, Floyd

#374

I was concerned about the resulting voltage if the 5R4 is replaced with diodes.? Our line voltage here can be up to 124 VAC and I understand the design line voltage for the Ranger was 115 VAC.? While the 6146 can handle the higher voltage, I think it would exceed the recommended max for the 1614 modulators and who knows the effect on the modulation transformer.? Probably best to pass on the 5R4 replacement.? Regarding the regulated 300V supply - did you use the circuit that WA3DSP published in 2013?? That one regulates the 300V to all circuits and provides 150v regulated for the VFO screen.??

?

I use the Ranger on CW in contests and it took only one such operation to grow tired of the need for two switch operations (Operate switch to STBY, Crystal/VFO switch to ZERO) when doing search-and-pounce operation.? I made a change to the Crystal/VFO switch (eliminated the crystal selection and connected the VFO output to V3 grid all the time) and that freed up some contacts to close the key line when switching to ZERO.? So, now just a single switch operation.?

?

73, Floyd - K8AC

#375

Floyd Hello

??? OUR POV is the really high 6146 EP does not get you anything much in terms of RF output, but it does, from our POV, generate a whole pile of HV related issues and problems. ( AKA component stresses). Given that Ranger modulation transformers are less available than chickens with teeth, we err on the side of caution.

??? Yes, we use the +300V solid state regulator from WA3DSP, however the +150 regulator for the VFO screen is moved into the VFO shroud. As we noted earlier, all that gas regulator tube/ dropping resistor monkey-motion is removed and discarded.

???? Thank You very much for your comments.

Ashley

I was concerned about the resulting voltage if the 5R4 is replaced with diodes.? Our line voltage here can be up to 124 VAC and I understand the design line voltage for the Ranger was 115 VAC.? While the 6146 can handle the higher voltage, I think it would exceed the recommended max for the 1614 modulators and who knows the effect on the modulation transformer.? Probably best to pass on the 5R4 replacement.? Regarding the regulated 300V supply - did you use the circuit that WA3DSP published in 2013?? That one regulates the 300V to all circuits and provides 150v regulated for the VFO screen.??

?

Thank You

Kiss-Electronics

Ms Ashley Hall

183 N 5th PL.

Cornelius, Oregon

97113

?

W7DUZ

?

On Friday, January 31, 2025 at 01:12:40 PM PST, Floyd - K8AC via groups.io <floydsense@...> wrote:

I was concerned about the resulting voltage if the 5R4 is replaced with diodes.? Our line voltage here can be up to 124 VAC and I understand the design line voltage for the Ranger was 115 VAC.? While the 6146 can handle the higher voltage, I think it would exceed the recommended max for the 1614 modulators and who knows the effect on the modulation transformer.? Probably best to pass on the 5R4 replacement.? Regarding the regulated 300V supply - did you use the circuit that WA3DSP published in 2013?? That one regulates the 300V to all circuits and provides 150v regulated for the VFO screen.??

?

I use the Ranger on CW in contests and it took only one such operation to grow tired of the need for two switch operations (Operate switch to STBY, Crystal/VFO switch to ZERO) when doing search-and-pounce operation.? I made a change to the Crystal/VFO switch (eliminated the crystal selection and connected the VFO output to V3 grid all the time) and that freed up some contacts to close the key line when switching to ZERO.? So, now just a single switch operation.?

?

73, Floyd - K8AC

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Ranger solid-state rectifiers