The AM Forum

Does anyone know of a suitable replacement for the low voltage choke (LP2) in a Ranger 1? Thanks! KD2WW

Its a 15 H choke.  the manual is here          http://bama.edebris.com/manuals/

I have a Ranger 2; the schizmatic for the pwr supply section is the same. Anything about the same physical size rated for roughly 400 volts should work.......

Dont know how much/far you've got into this thing,or want to, so MY MINIMUN Operational and SAFETY recomendations are..

R3, the famous 18K "chernoble " resistor..  replace with at 10 watt, 18K... most people move it outside the vfo box; you can if u want to

the LV filter cap.. 30uF..  fatten it up.. a 100uF 450V makes a nice replacement; whatever u have bigger than the 30 will be better than whats in there now.  The HV cap 10uF, its a joke, two 100uF 450V in series w/ bleeders will give you a nice improvement.  The C90A/B kluge can be looked at and replaced.
Replace the pwr cord with a 3 prong;  get rid of the fuse block thing and install a fuse in the hot side. You can use an inline fuse holder if you dont want to put in a panel mount in the back...     

Check out the AM Window site for the TimTron modifications and a lot more background info for this spaceheater...  klc

Thank You for the reply! I made the modification to move the vfo resistor and minor capacitor changes. The Ranger worked very well until the choke vented smoke during the Classic Exchange . Merrill, KD2WW

Hammond has an extensive line of chokes. There's got to be something here that will work:

http://www.hammondmfg.com/153.htm

Darrell, WA5VGO

Thanks for your link! I checked the Hammond line and found their 15 H choke was too large to fit in the available space. Merrill, KD2WW

You can bite the bullet and order a Peter Dahl replacement.... BIG $$$$...  Or try placing a want into the want section of the board. Someone here may have an odd choke surplus tho their needs. 

You got two fests in Joyzey next week. maybee try there......  klc

The low voltage supply choke in the ranger is very marginal, especially if you run the final off the low voltage supply while keeping the modulators running off the high voltage supply.  I have smoked 2 low voltage chokes over the years.  When I solid stated the HV and LV supplies, I did that below the chassis and attached the diodes to pins on the original tube socket.  That left a lot of room on top of the chassis.  I found a Stancor choke with end bells that fit perfectly on top of the chassis.  I painted the choke with automotive underhood black and it matched the other iron very well.  To the eye it looks very original.  When the new larger choke was installed, that raise the supply voltage to about 380 and that gave me slightly higher output power from the final as compared to using the original choke choke while running the final on the LV supply.  I can't remember the exact inductance of the new LV choke, but I am sure its value is not overly critical especially when you add extra "C" in the supply.  I ended up with 100ufd in the LV supply.  That gave me just the right abount of voltage on the final to drive the 3-500Z's to about 300W output.  The choke runs stone cold and the regulation is fantastic. 
joe GMS   

Joe,
Thanks for the suggestions! I installed a junkbox choke of the proper dimensions and a bit lower resistance , replaced the low voltage rectifier and am back on the air. I cannot hear a difference in the audio quality with the substitute choke so I think you are correct about the value not being too critical. Solid stating the supplies is my next project, and I was wondering if you added any resistors to drop the voltage.
Merrill, KD2WW

Merrill,
I did not add any series resistance and have not had a problem.  I solid stated the power supply some 15 years ago and all has been fine.  You really want to keep the rectifier impedance as low as possible.  That helps big time with dynamic load changes.  I did put the 18K 5W VR dropping resistor below deck.  I have many Ranger Audio Mods that I am documenting and should have available shortly.  Stay Tuned!
joe GMS