[Boatanchors] Xtal needed maybe?

[Glen Zook]

Sometimes a 12 MHz crystal was used (I have done this when I did not have a 24 MHz crystal available) and doubled to 24 MHz.  This would then give an i.f. of 26 MHz to 30 MHz for the 50 MHz to 54 MHz coverage.  Such was done to use receivers like the Collins 75A-2 and 75A-3 as the i.f. receivers since they cover 26.0 MHz to 28.0 MHz when in the 11 meter bandswitch position and 28.0 MHz to 30.0 MHz when in the 10 meter bandswitch position.

The performance of the converter is the same whether or not a 12 MHz or 24 MHz crystal is used.

Since I have both a 75A-2 and a 75A-3 receiver I have set up a number of my 6 meter and 2 meter converters (as well as 222 MHz converters) to use the 26 MHz to 30 MHz range as the output.

The 49.4 MHz crystal is used when the converter has an AM broadcast band receiver for the i.f.

Replacing the Motorola connectors with BNC connectors was a very common modification to the AMECO CB- series and CN- series converters.

I have converters marked CN that are for 6-meters, 2-meters, and the 222 MHz band.  Only one of my 6-meter CN type converters is marked CN-50 and that marking is not on the end where the gain potentiometer is located but is stamped with probably a rubber stamp on the top of the chassis.

Now the miniature tube type AMECO converters were marked with the band with the CB-6 for 6-meters and the CB-2 for 2-meters being the most common.

Being somewhat of a "converter nut" I have over 20 of the various AMECO converters for the 50 MHz, 144 MHz, and 222 MHz regions.

Glen, K9STH

Website:  http://k9sth.com


--- On Sat, 6/21/08, telegrapher at att.net <telegrapher at att.net> wrote:

Last year i bought an AMECO  VHF COnverter model CN.  I didn't have any paper work on it at the time. but finally found it someplace due to a list members referral. Got to looking at it today and realized that the Xtal frequency is not right for 6 meters.  It has a 12 mc rock whereas the tables in the manual (so to speak) show 43 Mc for a down conversion to the 7-11 Mc range for 50-54 mc coverage.  To cover 50-51 mc it recommends a 49.4 Mc rock. 
 
So does anyone out there have such an animal?  49.4 Mc or 43 Mc. preferably.
 
Output to the Hf receiver is variable so even a 40, 36,24, 22 or 19.5 mc xtal would work.
 
Now this converter is marked as a "CN" and not a CN-50.  Maybe i'm looking at two different things here.  If you know if there is a difference, even though this one has written "6 mtr" on the side, drop me a line. I'll have to investigate this a little more it seems cause with a 12 Mc rock in it, the output would be 38-42 Mc.  Could it be that this is a 10 meter converter which would give me a 16-20 Mc output with the 12 Mc rock?  Also this unit has a BNC connector next to the 6J6 whereas the schematic for the CN-50 does not have that.  The Auto type connectors have been replaced by BNC type.