The AM Forum

Hello: What is L5 used, or adjusted to, in the plate circuit of the of the crystal osc, I can not find a single mention of this in my manual. I have had an issue where two of my crystals wont start, this only happens about five percent of the time. I did change out some resistors that were out of tolerance.

Thanks John W9BFO

   In the ranger 1 operation pdf that I have it says:

"
 The grid drive on 10 and 11 meters may be adjusted by peaking L5 in the
vicinity of 28 mc."

   I have never "Had" to play with it.

GL

/Dan

On the Valiant, according to the manual, it's adjusted to provide peak grid drive at 28.6 MHz. I believe it's the same for the Ranger. What frequency do your crystals operate at? Are they designed for third overtone (for the higher bands)?

Grins & Giggles......for the two crystals that will not start: Try twisting that big VFO knobby........might find a sweet spot where they will work.

Gotta Viking 500 that wants the VFO knob in a special place before some crystals get with the program.

Craig,

Thanks guys for the replys, I will use that vfo trick, I still cant find anything in the manual about it.

John W9BFO

Hey John,

    Yes, that is correct. I only see one mention of it
in the document titled "operation manual  Viking Ranger
Transmitter/exciter" dated 1/55. on page 24. The very
last line of text. Interesting to note that page 24 is
dated 10/57. This document has 48 pages.

    Another Ranger manual document has only 40 pages
and makes no mention of the L5 adjustment. This manual
has page dates of 6/54.

     The document titled "Operating Manual Viking
Ranger II Transmitter/Exciter" dated 3/61 also ignores
L5.

     More info may be found in the Valiant or 500 documents
as Craig has suggested.

    Life before Word Processors.

/Dan

Another mystery adjustment is L17 in Valiants. It seems to be a means of increasing drive on 40 meters. Depending on the version of manual you have, it is:

1) not mentioned
2) adjusted for max drive (grid current) on 40 meters at 7.33 mHz
3) adjusted so that the slug is all the way out (counterclockwise)

My experience is that peaking the drive (2) causes nasty VFO chirp and FMing. Setting it as in (3) yields a clean signal with only the slightest sacrifice in grid current.

This lesson burned up a lot of my time thanks to conflicting printed instructions and I hope others won't have to re-invent the wheel.

A little OT …

I refurbed a Ranger II recently.  There's an interesting error in the manual related to L5.  Manual says to adjust L5 to peak drive on BOTH 10 and 6 meters.

I had very low drive on 6, so without thinking further about it, proceeded to try to peak 6M drive with L5.  Of course, that doesn't work.  So after screwing with L5, I did have to readjust it to get 10M drive back up.  My recollection is that its tuning was relatively broad, but my memory is as old as I am.  I do wish Johnson had used a Phillips or hex as the adjusting screw on L5 instead of the slotted type.  Hard to keep the tuning wand/screwdriver from slipping since there's a lot of cranking involved to move the relatively stiff slug through it's movement range.

A quick stare at the schematic revealed the error in the manual — L37 is used to peak the doubler for 6M.  There's no reference to L37 in the text of any of the Ranger II manuals I have.  But that (and a fresh 5763 doubler tube) solved the drive problem on 6M.

Grant NQ5T

Thanks Grant, have the same problem on 6 meters, will try what you said