[Heathkit] OT: Emmco Dial (??)

[Phil]

Don't know where else to ask, (I don't post a question on the regen 
group).  But I figure there are a lot of oldtimers out here. . .


Today a "care package" arrived with the Audio chokes I was expecting for 
the audio filters in the regen I'm gathering stuff for.

Anyway, among the "goodies" were some tube sockets, a couple RF chokes, 
but the REAL "treasure" has to be the "Emmco Dial" that he included.  
When I first saw it I thought it might be a National Dial sort of like 
the ones on National HRO receivers (only smaller).  But this one is 
entirely different.  It is completely round, 4" in diameter, flat, brown 
plastic or phenolic (maybe Bakelite I really can't tell the difference) 
with a really fine (as in very small) embossed checkerboard pattern 
texture.

In the front middle is a brass/chrome dome like thingy that has a 
setscrew and itself screws out of the dial.  This piece is 1/4 inch and 
looks like it'd accept a 1/4" shaft.  Below the "dome" is the actual 
tuning knob, black with an arrow (probably not original) that drives the 
main dial on the back of the shaft via a slotted piece (sort of like the 
plastic Heathkit Vernier dials of the HW-SB series).

At the top outer edge is the main window where the the numbers 0-100 (by 
10's) appear as you turn it, plus 1 hash-mark for each division (must be 
a 100 of them).  On the outer edge of either side is a small window (in 
line with the "chrome-dome" thingy) where a single number may appear in 
parts of the rotation.  Through a "masking system" numbers only appear 
in either the left or right window at a time.

The dial turns quite stiffly, but I don't want to do anything rash to it 
til I know more about it and how to service it.

This dial has to be a real jewel, I Googled "Emmco Dial" and it only 
turned up two hits, one from a 1930's Crystal set article from a 
newspaper, and the other from a listing of old radio stuff in a 2008 
auction, no pictures.

Help!  Anybody know anything about this dial?

-- 
73 de Phil,  KO6BB
http://www.qsl.net/ko6bb/  (Web Page)

PRESENT RADIOS:
Grundigs:    S-350 (~2006), G6 (2011) & S450DLX (2014).
Icom:        R-75 With Cascaded 250 & 125Hz CW Filters. (~2005)
Icom:        IC-7200 Transceiver (~2015).
Radio Shack: DX-380 digital portable (~1990).
Zenith:      Royal-7000 Transoceanic Portable (~1968).

ACCESSORIES:  Homebrew LF-MF Pre-Amp, MFJ-993B HF Auto-Tuner.
               Homebrew 8 Hz Audio Filter.

ANTENNAS:  88 foot Long Ladder-line fed dipole at 35 feet AGL.
            Active Mini-Whip at 36 Feet AGL for LF/MW.
            37 foot "Low Noise Vertical" at 11 feet AGL for LF/MW/SW.

Merced, Central California, 37, 18, 37N   120, 30, 6W CM97rh