[Boatanchors] HP 5245L/5243B Freq counter question

[Philip Atchley]

Hi,

I'm not on the Test Equip list so I thought I'd ask the question here 
(and this sucker is heavy/old enough to qualify as a BA).

I'm the proud owner of a Hewlett Packard 5245L frequency counter 
(remember those Nixies) with the 5258A Sensitive Pre-scaler (good to 200 
MC).  Anyway, it works well and seems to be fairly accurate, and I like 
the timebase outputs on the back.  With that prescaler it is quite 
sensitive for "sniffing" weak RF.

The question is concerning a 5253B Frequency Converter plug-in good to 
500 MC.  I have the 5253B converter sitting here and will be returning 
it to it's owner this weekend.  I checked it out for him and it "seems" 
to work FB.  It's been a good 30+ years since I last used one and I 
recall that you put in an unknown signal over 50 MC and tune it to peak 
the meter and obtain two different readings.  There is then some "math" 
involved to obtain the "true" frequency reading, but I don't recall what 
it is.

The operation of the plug-ins don't seem to be covered in the (loaned) 
5245L Service Manual.  But I'd like to return the plug-in to it's owner 
with instructions on "How To Use It", at least in a basic format.

Help!

73 de Phil,  KO6BB
991 Different NDB's heard to date.

http://www.geocities.com/ko6bb/
Merced, Central California, 37.3N  120.48W  CM97sh