[Hallicrafters] SX-111 Crystal Calibrator

[Roy Morgan]

At 08:39 PM 4/1/03 +0600, Bill wrote:
>  I noticed it was something else and thought
>it might be a crystal in a glass envelope. ... Is it a crystal in a tube 
>envelope?
>Is it in a vacuum?

Bill and others,

Here is  info I posted two years ago about the calibrators in the 
Hallicrafters radios. You may find it interesting:



At 11:35 AM 4/4/00 -0500, Michael Smith wrote:

I am wondering if anyone can tell me if the octal socket 100 kHz crystals
Hallicrafters used for various receivers are all the same. I have pondered
this and it seems that if they were in that package that a crystal from one
receiver would work in the others. Yes?  I really need a crystal that I can
plug into this SX-100.

Update:

 From Electric Radio, Number 75, July 1995 article
"The Hallicrafters HA-7 100 kHz Crystal Calibrator"
by Dave Ishamel, WA6VVL
118 Paularino Ave.
Costa Mesa, CA 92626

The Hallicrafters HA-7 100 KHz crystal oscillator/calibrator ....
2-5/8" L x 1-5/8" W x 1-1/4" H..
The calibrator uses a unique Northern Engineering Laboratories 100 KHz T-9 
crystal that has the size and looks of a 6V6GT, including the octal base.
...  The first mention of the HA-7 option was with the introduction of the 
SX-122 receiver in April '64.  It was priced at $19.95.

    The HA-7's genesis was the 100 kHz oscillator/calibrator used in the 
SX-100, SX-101/101A and SX-111.  This calibrator dates to the introduction 
of the SX-100 in September '55, and is almost identical to the HA-7 with 
two exceptions:  The enclosure is 1/4" deeper and has two additional 
manufactured ears.   The Hallicrafters P/N for this calibrator is 
001-902508 ....

The Northern Engineering Laboratories, Inc. T-9 crystal was specified at 
100.000 kHz +/-5hz at 25 oC.  The specified load capacitance was 20 pF.  A 
source at NEL said that the T-9 Crystal was made in both DT (T-9D) and 
E  (T-9E) cuts.  The DT cut's temperature coefficient is approximately half 
that of the E. . The T-9D crystal is used  (only) in the SX-101/101A with a 
Hallicrafters P/N 019-1011915.  The T-9E with P/N 019-202351 is used in the 
SX-100, SX-111, SX-117,and SX-122/122A with the HA-7 option  The T-9D is no 
longer cost effective to manufacture because of the amount "of the quartz 
that would have to be committed".  The T-9E is still available from NEL, 
but I was unable to get a quote on price.  NEL's minimum order is $125.
   Northern Engineering Laboratories, Inc. was founded in '54 .... The 
company's name has changed to NEL Frequency Controls, Inc.
   I tested the SX-100's calibrator and the HA-7 from my SX-117 and made 
the following observations:
   *...
   *The HA-7's temperature coefficient using the T-9E crystal is 
approximately +0.05 Hz/oC.  The temperature rise in the SX-117 during the 
first two hours of  operation is approximately 19oC which corresponds to a 
+/-0.85 Hz increase at the fundamental 100KHz or 85 Hz at the 10 MHz WWV 
calibration point.  It is probably best to calibrate the HA-7 in the host 
receiver after two hours or more warm-up if maximum accuracy on the higher 
bands is required.
   *The voltage coefficient from 125-175 VDC is +0.025 Hz/V or +0.25 
ppm/V.  The HA-7 should be powered from a regulated source for best results 
(e.g., +150 VDC from an OA2).

(From the article schematic of the HA-7):
The tube employed is a 6AU6.
Base plug connections are as follows:
1. ground
2. B+
3. Signal out (from a diode to the plate)
5. Filament (6.3 V)

(End of article quote)

I found NEL Frequency Controls on the web at: http://www.nelfc.com/
      NEL Frequency Controls, Inc.
      357 Beloit St.,
      Burlington, WI 53105-0457.
      T | (262) 763-3591
      F | (262) 763-2881
      E | sales at nelfc.com
      W | www.nelfc.com

Notes:
1) the crystal oscillator/calibrator uses one 6AU6 tube, the octal crystal, 
and associated circuitry.  You cannot just plug a crystal into the chassis 
socket in your radio and have it work.  Home-brewing a substitute unit 
should not present any difficulty.

2) It appears that either the early or later calibrator will work in any of 
the radios mentioned, but you should CHECK the connections before you plug 
one in.

3) At least one NEL octal crystal has been bought at a hamfest for one 
dollar from a vendor who may not have known what it was.  Said crystal is 
not now for sale.  Those who seek these crystals are advised to remain 
alert at hamfests.

4) Although the article calls  the crystal unit "unique", it may not be 
unique.  Both the PR company and the James Knight company made similar 
glass-encased, octal-based crystals, some of which were cut for 100 Kc.

Happy calibrating!

Roy


- Roy Morgan, K1LKY since 1959 - Keep 'em Glowing!
7130 Panorama Drive, Derwood MD 20855
Home: 301-330-8828 Work: Voice: 301-975-3254,  Fax: 301-948-6213
roy.morgan at nist.gov --