Johnson ranger 2 and n3zi vfo

[kc2etm]

Hi I have a ranger 2 and I was given a n3zi vfo and buffer amp
Can I simply feed this directly to a crystal slot then just switch the band switch
To the band I'm tuning?

[w7fox]

It depends on how good the buffer amp is.  I tried the n3zi vfo, which works fine but it has very low output.  I built the Hagerty amp, and it works well on my Viking l, but I had to increase the gain of the op amp to do it.

[W2VW]

Higher bands multiply the VFO frequency and will not work all the way through the chain.

This may be an issue for direct readout.

[kc2etm]

Thanks I was able to get everything working but I shorted the type plate cap to ground
Before letting it bleed off and I took something out its either a choke or resistors tied to the bottom of the plate choke in parrellel with a capacitor I believe it to be either l10 or l13
I turned it on after I did it the part begins to smoke and plate current is high
pegs plate scale when I key it up I will try to attach a picture

[kc2etm]

Well I found from some reading that the burned part should be a 4.5 microhenry choke so I changed and it seems to load to full carrier ok
But all my meter reading are low osc buff and grid barely tickle the needle
They were pretty low before this anyway all under 2ma but now almost non existent
And now the audio is very scratchy and distorted

[kc2etm]

Well as it turns out some one put protection diodes across the meter terminals and one went shorted changed them out now meter is working as it should except my plate current reads about 75ma fully loaded into a dummy load the book says it should be around 135ma it is showing full output on watt meter and full modulation on the scope strangely I do not find any shunts between meter mode switch and meter as they show in the book
Any hints?

[W3GMS]

Check your plate current with another meter in series with the HV going to the base of the RF choke closest to the power supply.  Meter shunts are known to go bad on these old rigs.  If you external analog meter agrees with the internal meter then check your screen voltage on the final.  Low screen voltage will limit your plate current.  You should be able to easily get 2.5 MA of grid current.  If you can't, fix that problem first and then go on to the 6146.  Also try an known good 6146. A good watt meter is handy as well.  When the rig is fully loaded the output should be around 40W or so.     

Joe, W3GMS   

[kc2etm]

Hi thanks for the help I do have good osc buffer and grid current reading now
It's just the plate reading thats low now but i do believe it to be a false reading because it does do the full 40 watts and even a little more if I push it

[W3GMS]

Hi thanks for the help I do have good osc buffer and grid current reading now
It's just the plate reading thats low now but i do believe it to be a false reading because it does do the full 40 watts and even a little more if I push it

As mentioned, check the plate current with a good analog meter and if you find the reading is fine with the alternate meter then replace the shunt resistor.  I think the last time I replaced on, I got it from Mouser.  If you want to walk the meter on, go slightly higher in value for the shunt and then parallel higher value resistors until both your external analog meter and the panel meter reads the same.  Some people care and others do not, so whatever floats your boat!  I like my meters to read accurate!! 

As always, your dealing with high voltages so use all the precautions when dealing with deadly voltages! 

73,
Joe, W3GMS   

[kc2etm]

Ok I checked with an external meter and readings do jive with the internal meter
So what pin on the final do I check for screen voltage also will it still do its full output power as it is doing right now with the low screen voltage?

[kc2etm]

This may be of some importance there is a small extra pot mounted on my keyer board
That is not factor I do see some plate movement when I adjust it could this be adjustable bias mod

[W3GMS]

That is the keyer tube.  It just allows one to control the shape of the keyed waveform.  The pot is normally mounted on a small shelf with the bias rectifier. 
Check the screen voltage at the screen pin of the tube.  As you lower the screen voltage the output drops but its not a linear relationship.  The screen voltage is derived from the HV on the Ranger.  X amount of screen current times X amount of resistance is the voltage drop across the screen dropping resistor.  Also make sure you HV is where it should be.  If the clamper tube is conducting, that will  lower your screen voltage.  With proper drive to the PA, it should not be conducting.  It only should conduct when you don't have drive.  If your careful, unplug the clamper tube and see if you get more IPA.  But make sure you plug the tube back in if you have the HV on and no drive to the final otherwise you will have excessive plate current. 

Also try another 6146.       

Joe, W3GMS     

[kc2etm]

Ok I found a high resistor changed it and now have plate current
As for the keyer shelf there is two pots the standard keyer adjustment
Then another one that is a 10k with a 2.7k resistor and a Zener diode it seems
To be the timtron adjustable modulator bias now my question is how do I adjust this modulator bias? What do I set it at

[W3GMS]

Look at your manual!  If I remember I think the bias is somewhere around 70 Ma.

I can't possible know what mods were done to your rig.  As far as setting the bias, put it in AM, no audio and the meter switch in the mod position and adjust for the recommended idling plate current.   

Joe, W3GMS

[kc2etm]

You were right set between 55 and 70 she seems to be working good now I will
Have to try and get an on air check tonight after these storms are done thanks
For all you help

[W3GMS]

My pleasure and always glad to help.  I see your kind of new to Amateur Radio and its great that you have an interest in this old stuff! 

If you don't already have one, look for a good scope.  If you get a bench type of scope you can use it to do some great trouble shooting as well as monitor your output signal, such as percentage of modulation. 

The Ranger transmitter is a great rig.  It has lots of potential either stock or maybe later on super charged a bit! 

Hope to work you either on 75 or 40 meters sometime. 

Have fun,
Joe, W3GMS