The AM Forum

This is to all those Ranger experts out there. I am having a weird effect with the 6146 plate current. My Ranger has all the WA1HLR/WA1HZK PTT keying mods. The 6146 plate current always shows to be about 20ma on the meter. What is happening is when I key down (PTT) for a extended period of time I notice that the current will climb slightly from about 130 to about 140ma. Then when I unkey the current will drop to  about 50ma and then gradually drop back to the normal 20ma level until I key again. It's like something is heating up and then cooling slowly after I unkey. Has anyone else noticed this? Is this possibly some effect from the PTT mods? Possibly this is normal. Everything seems to work well, its just one of those things. Thanks, Randy, wb5kcm

Randy,
         The basic ranger has no fixed control grid biass on the final (at least the older ones) It uses only grid leak bias, (so you have to actually drive it into class c operation. It shuts down the final in standby by clamping off the screen voltage. If something in the screen clamper circuit is not right (like an out of tolerence resistor) the final will not cut off properly. Check out all of the resistors in the screen clamper circuit, the 6AQ5 tube, and the coupling cap to the driver plate. Also check to be sure that your PTT relay has good low resistance contacts. It is not totally unusual to see a small amount of standby plate current, but it should be very small.

                                               the Slab Bacon

The current you are reading during standby is basically what is being drawn by the clamper tube if the circuit is working as designed.  One of the symptoms when my clamper tube developed heater/cathode leakage was increased standby current and it progressed into a pronounced hum on the signal.

The Ranger does put a lot of heat into a small box, especially since it does not have a separate HV transformer which is cut off during receive.  The shack cat likes the top of the Valiant as a snoozing spot (especially since I added inrush current limiting and got rid of the Valiant start-up "bonging" sound); I think only a desert scorpion would think my Ranger is a suitable place to sleep. 

Rodger WQ9E

Hmmmmm................. I bet the smell of cat hair burning off of the plate tank smells yummy................. ;D ;D

Rodger,
          Seriously, if you do some of Timmy's mods to the ranger, it dramatically reduces the amount of heat that comes out of the top of it. They actually run pretty cool after you do away with some of the nasty dissipation from the original bleeder / voltage divider circuits. At least mine does.

And I kinda like the "bonging" sound when you throw the plate switch on my valiant. I guess I'm just used to it.
                             
                                                the Slab Bacon

I do plan to go back into the Ranger and make those mods to cool it off a bit.  I was in a bit of a hurry to get it going since I had spent about a month getting my Desk KW ready for testing and impatience set in.  I bought the Ranger 1 and the Desk KW at the same time and the Desk KW had been completely taken apart and the panels had been newly painted and silk screened along with the Ranger front panel.  By the time I took care of some issues with the Desk (rebuilt the mode switch, replaced the main plate relay with a pair of solid state units, and took care of some wiring harness issues)  and then put everything together again I was ready for a test so I basically put the Ranger in working order and put them on the air.   The closest I have come to a ham radio heart attack was when I first tested the unit outside of the pedestal and as I was watching/listening/smelling for trouble I changed the mode switch from CW to AM and the modulation transformer shorting relay is really loud, especially when you are watching for problems.  I would have jumped about 8 feet but the barn room only provided 7.5 feet of clearance.   Now that I have had them for a couple of years it is time to go back and do some more to the Ranger-after I finish testing my "new" Viking 500 and restore my recently acquired S line and repair my ice damaged 4 element quad, etc. etc.)

I removed the Valiant bong noise shortly after the plate relay stuck on and immediately applied HV AC to the cold MV rectifiers.  I decided at that point to solid state the 866A's and add some protection to the transformer.  I had a Valiant as my first novice rig in 1974 and so it occupies a warm spot in my heart (and in the shack!).  Daphne the siamese cat will paw at the Valiant to let me know it is time to power it up; she apparently likes heat and RF.

Rodger WQ9E

that because it reminds you of dropping a big maw down.

(directed at the Slab)

Thanks for the responses. I will check into the clamper tube and circuit. Also will check my PTT relay contacts. 73, Randy

Yea, but when I "drop the maul" on the big rig (the 4X1) The only thing you hear is the auxillary fans spool up. Hmmm............. Kinda bass ackwards!! ;D ;D

Rodger,
         I have NEVER had a flashover from the 866s in my valiant!! I fire mine up and as soon as I get a spot signal, I hit the plate switch. I've never had a problem. I doubt that you could flash over the 866s in a valiant, the voltage is just too low. Keep in mind that in the valiant, 866s were chosen as rectifiers for their CURRENT handling capacity and not for the voltage. At 650v, I doubt that they will ever flash over. However with all of the plate amd modder current a standard vacuum rectifier coudnt handle it.

One thing that I forgot yesterday, is that a ranger is one of the few transmitters that actually have the plate current meter in series with the plate feed. (most times it is actually in the cathode lead). Since the screen supply is tapped down from the plate feed to the final, when the screen is clamped down in standby, the meter will actually show the current being drawn through the screen dropping resistor. Henceforth the small amount of residual current shown on the plate meter when in "standby".

I remembered this when I was driving home yesterday.

                                                     The Slab Bacon

My Ranger is blowing the 5 amp primary fuse every once in a while when I turn it on. I have checked for any kind of intermittent short but unable to find anything. What I am suspecting is inrush current. My Ranger has all the power supply mods. Solid state HV and LV power supplies with 330mfd LV cap and 165mfd HV cap. At first did not suspect inrush current due to having choke input filters but I suppose with the solid state rectifiers and the large caps it maybe happening. Does anyone have any suggestions to limit this inrush current in the Ranger. Also, does anyone know what the Ranger's nominal current consumption is from the 117 VAC source under full load? Any info is appreciated. 73, Randy :(

Hi Randy,

With those large caps and solid state rectifiers....in-rush current is very likely your problem.  You might want to consider some series resistors to limit current and drop the voltage a bit, since the solid state rectifiers will not have equivalent voltage drop or the delay in coming on that you had with the tube rectifiers.  Also, a simple step-start circuit might be a solution to gradually turn things up.   There are a number of circuits out there for doing that.  Those big 'lytics might look almost like a dead short when things first crank-up.  That is a whole lot more filter capacitance than the original!  Just some thoughts.....

73,  Jack, W9GT

Hi Slab,

I think the flashover was the result of the plate relay being stuck on so the 866's saw AC plate voltage prior to any warmup.  After the "event" both 866's had glowing cathodes but one was barely conducting so I ended up with about a 5/8 wave rectifier.  I agree that with the fairly low plate voltage in the Valiant flashover should not normally be a problem.  The most common HV rectifier problem in the Valiant was probably due to the use of standard hook-up wire being used for the LV transformer to 866A cathode wiring.  I have seen several that had arced and burnt wiring due to this problem. 

I am keeping a couple of rigs with MV rectifiers in them, my Hallicrafters HT-19 CW/NBFM transmitter and a Heath HA-10 amplifier.  My Johnson Desk, 500, and Tbolt all had plug in solid state replacements when I acquired them.

73, Rodger WQ9E

Randy,

I would imagine your fuse popping is due to the greatly increased filter capacitor size.  Over time, your power switch, transformer, rectifiers, and choke are not going to like this added stress.  The easiest thing to do is add an inrush current limiter.  This device should be installed in series with the "hot" or "load" lead to the power transformer.  These devices have a fairly high cold resistance which drops quickly to a very low value.  They are rated by their cold resistance value and their rated current capacity so select one that has a high initial resistance and a rated current value equal to around 110 to 120% of what you expect the transmitter to draw (with it running AM phone and loaded to rated input).  You can get these from Mouser and Digikey and they should be under $3.  They look like an MOV or ceramic disc cap and have no moving parts, are easy to use, and are highly reliable.  The only caveat is that they generate a fair amount of heat in operation so don't mount it directly against one of your filter caps are anything else that is highly heat sensitive.

73, Rodger WQ9E

R
If ur real cheep, you can use what I use for a variac replacement. You'll need a 120 v wall switch and a lamp socket. Wire the lamp socket in series with the hot side of your 120V. Wire the switch accross the socket. Screw in a 120 V lamp. Plug the Ranger into this jig.  When you switch on the ranger, you'll have a current limiter in the lamp. This will let the caps charge up a bit; you then switch "ON" the switch connected accross the lamp, taking it out of the circuit....

What I did was go to Home Despot and get a " Motor Fused Covers w/Single Pole Switch for Handy Box  15A - 125V AC"
It is what the name says. All the parts needed (but the wire, plug, socket, lamp). Its got the switch, the lamp socket AKA fuse socket .  BUT, I use it 'as is' with a lamp and do not use it as a component in equipment. .. YOU would have to set this up with the switch accross the socket.. all you need to add to the device is a 'handy box' they got 'em there , just ask...

If you have some screw in fuses, they can be used in this setup as a normal fuse...  as u probably know, a 60 W 120V lamp acts as a 1/2 amp fuse, 120W as a 1 A .          klc

Thanks for the responses. Wow, some really good info! I will look into the "inrush current limiter". I have read some about the Thermistor. I will need to know what the max current needs for the Ranger. I will try and rig up a test with the meter and see what its drawing from the AC line at max AM modulated output.
And KC, thanks for your input, I will look into making one of your "variac substitutes", that could be used for a lot of things. With the right lamp, I could plug the Ranger and the HQ-170 both into it.
If anyone thinks of somthin keepem coming. 73, Randy

I cannot remember now which size inrush limiter I used in my Ranger 1 and checking the fuse ratings on Johnson gear is always "interesting".  I see that the original fuses called for in the manual are a 3 amp in one side of the line (slow blow I presume) and a 5 amp (normal) fuse in the other.  Based upon the power level and recommended fusing I would imagine that from the Mouser catalog:  http://www.mouser.com/catalog/629/459.pdf  the CL-80 would be the best choice and the CL-70 should also be suitable.

I guess now this thread will take on a new life on fuse plugs...  My personal preference is to replace the original with a 3 wire  with it fused only in the black or "hot" lead; I use an inline fuse under the chassis to avoid drilling new holes in the chassis or case.  If the fuse blows on a regular basis, it is either undersized or there is a problem that needs "fixin" so the transmitter needs to come out of the cabinet anyway.  If you really want to keep the original plug, I would make sure you follow the old rule of having the ground wired hooked up first and removed last.  Then I would mark the plug so that it should be plugged into the outlet one way only and put a proper value fuse in the "hot" lead and a much larger value slow blow fuse in the other side of the plug.  This way you should not end up with the situation of the neutral side of the cord being "open" due to a blown fuse.  And yes I realize this whole plug issue is a controversial topic and the original style plug is still available at Farm and Fleet and other farm type stores.

73, Rodger WQ9E

I didn't know you guys had Farm & Fleet south of the state line Roger.  I always thought that like Fleet Farm (it's counterpart, which basically from Milwaukee northward), Farm & Fleet was basically a Wisconsin company (both were originally the same company until 30 plus years ago, when the two partners, Mills & Blaine, split the company up over a dispute, with one getting the territory south of Milwaukee, and the other one getting the territory north of Milwaukee).  I assume that like Fleet Farm, they call Farm & Fleet, "The Men's Mall"?

Ellen - AF9J

I have also seen those original type fused plugs at Rural King stores here in Indiana.  They are used on electric fence chargers.  I agree, it is, at least, a good idea to identify the "ground side" and mark it to properly plug it into an outlet.  Certainly, the inboard fuse and the 3 wire cord is a good protective measure.

73,  Jack, W9GT

Hi Ellen,

Yes, Farm and Fleet is alive and well in central IL!  Between buying yard supplies, softener salt, and other sundries I am in about once a week.  They used to be a good source for tower hardware but their newer turnbuckles and clamps don't appear to be galvanized as well as the old.  My wife is a N. Dakota native and so I have been in the Fleet Farm stores over in the ND and MN area.

I guess you can still call F&F the men's mall but one of my colleagues grew up in a fairly exclusive part of N. Dallas, TX and used to buy her clothes at high end exclusive women's wear shops and she began buying a lot of clothes at Farm and Fleet.  She once remarked that if her high school friends saw her shopping there they would drop dead of shock.  I have bought quite a bit of clothes for my 3 year old daughter at F and F also.

How goes progress with the Cheyenne???

73, Rodger WQ9E

Hi Roger,

Thanks the John, W3JN I have a line on some connectors for it.  It's in decent shape externally, as is the power supply.  But it is stiff and dusty on the controls.  So, it hasn't been used in quite some time.  It would be my luck, that as a result of this, the caps are toast.  I'm hoping to dig into it tomorrow, and do some cleanup.  I need to get a manual (I may have a line on one), since the one on BAMA is very incomplete.  I'll try to get on the Midwest Vintage Swap net tomorrow morning, but the noise I'm having from the power lines, CFCs, and sundry devices in my apartment building has gotten so severe (about 10 to 20 over 9 levels) on 80, 75, & 160, that they are almost unusable.  I have to go to a hair appointment after work, but if I have time, I'm going to scoot up to AES, and cough up some money for a Timewave ANC-4 noise canceller.  Loops to null out my noise, are doing me no good.

73,
Ellen - AF9J
Going googly eyed looking at circuit board assemblies, under a microscope

Roger, WQ9E, what do you think about running two CL-90's in parallel? That would give me 60 ohms cold and 4 Amps capability?
Randy

Hi Randy,

The problem is that these devices are never perfectly matched so if you try to run them in parallel one will end up carrying most of the current and overheat.  You can use inrush limiters in series if you wish, however they are going to have a little "on" resistance and too much resistance will reduce the power supply dynamic regulation.  A single CL-80 is rated for a steady state current of 3 amps and I have not measured my Ranger but I think a pretty close estimate would be around 1.5 amps steady (loaded to rated power on AM phone) with slightly higher current draw on modulation peaks. This capability coupled with the 47 ohm cold resistance should be a perfect match for the Ranger 1.  I am pretty sure this is the value I used on my Ranger 1, unfortunately I didn't mark the value on the schematic and it is a fairly major pain to disconnect the Ranger 1 from the cables connecting it to the Johnson Desk KW.

To look at it another way, if the average current draw exceeds 3 amps then the fuse Johnson specified in the manual would not have held up anyway.

73, Rodger WQ9E

Roger, Thanks, I will take your advice. No need to take apart your Ranger. I am sure with all the mods to the Ranger the actual average current now is fairly low, maybe less than 2 amps. I want to put one of these Thermistors in my HQ-170 also. Thanks for the info.
73, Randy

Hi Randy,

You are welcome and hopefully the inrush current limiter will take care of the fuse blowing problem.  I keep quite a few of these devices on the bench and I generally add one (or more, the Viking 500 took four total for the different circuits) to each piece of vintage gear as I restore it.

I should have taking the Ranger apart down to the precision of a race car pit stop.  I have had to go inside it for three different hum problems (each at a different time, thanks Murphy!).  First the clamper tube caused a hum, then a couple of months later the keyer tube caused hum; but only on the VFO so I foolishly first took the VFO apart and replaced that tube which wasn't the problem.  Of course about 2 months ago the VFO tube decided to get in on the act and it had to be replaced.  I have never had hum problems with any other rig so I am really wondering what is up with this particular Ranger.  I probably should have had some holy water splashed on it over Easter to see if that would help.

73, Rodger

Ok Rodger, it sounds like you have had your share of issues with the Ranger. Hopefully you will have it all fixed where it will operate without hum for a long time. I bought my Ranger a couple months ago from a local ham here in the Dallas area and did not power it on due to it was in a stage of disassembly and still had all the old paper and electrolytic caps in it. So, I am unaware how it was operating before I did all the mods. Some of the minor issues that I am having now may have existed before I did the mods, not sure. I am thinking that I may have a wiring error or something. I keep going back over all the wiring trying to make sure everything is hooked up to the correct point. After I replaced the 6146 and the two 1614's it corrected most of the problems. Really the only thing I have now is the weird residual final current after its keyed for a period of time. As it was suggested, it's most likely something not quite correct in the clamper tube section. Also the inrush current fuse blowing. I just got back from the Belton, Texas hamfest yesterday afternoon. I have the Ranger opened up here on the bench now and will start working on it this week. Thanks for all your input. 73, Randy

Hi Randy,

I imagine you will find your odd current problem in the clamper circuit, most likely the 6AQ5 itself. 

I have every expectation that my Ranger 1 will now be a reliable producer of clean RF and AF for the Desk KW.  I had a Valiant as a novice and I have used a number of Johnson rigs over the years without reliability problems.  I imagine this particular Ranger had a lot of hours on the tubes before I got it and it has been trouble-free for at least 6 months of very frequent operation.  The Ranger/Desk KW/HRO-50 is my most used AM station.

I do think the Ranger will get a little vacation coming up as I finally finished going through my "new" Viking 500.  It got new filter caps, removal of some roughly installed audio mods, and a new resistor in the bias string to replace one that had tripled in value and kept it from working on AM.  I also went in and replaced the resistor in the VFO and cleaned and lubricated the reduction drive.  I spent several hours testing it into a dummy load today and everything is working as it should.  Next week I am pairing it with my Pierson KP-81 and will see how it plays on some of the AM nets.

73, Rodger WQ9E

 

Hey Rodger, Just got the thermistors put into the Ranger and the HQ-170. Both are working like a champ. While I had the Ranger open, I went ahead and mounted a fuse holder in the rear of the chassis and put in the grounded AC cable. I just put the fuse (5 amp) in line with the AC hot (black) lead. I had a spare 6146 here (Amperex with 1967 date code). With this new 6146 the weird plate current has stopped. I noticed that when I had this unkeyed plate current there was voltage on the 6146 screen and it would slowly drop off as the plate current dropped. With this new Amperex tube, all I show is abou 15ma on the meter. From what was told me in other messages this is normal. I suspect that the other 6146 is gassy or something causing this. I was on 3880 earlier and several stations gave me good signal reports..so I guess its working well now. Will look for you on the air. 73, Randy