[ARC5] Link frequency meter

[Christopher Bowne]

Ray - would be interested in knowing the details of the Camp Evans meter - xtal 
frequency and what the cal chart looks like.  The crystal in mine is 4.8875 Mc - 
39.1 Mc is the 8th harmonic.  The size of the cap and coil on the unit variable 
osc look like they are indeed working around 39 Mc.




________________________________
From: Ray Chase <raydio862 at verizon.net>
To: Christopher Bowne <aj1g at sbcglobal.net>; WA5CAB at cs.com; arc5 at mailman.qth.net
Sent: Thu, January 10, 2013 9:00:19 AM
Subject: Re: [ARC5] Link frequency meter

The frequency of the SCR-268 radar was set at about 205 Mhz. and shifting the 
frequency of its 16 tube ring oscillator was not a task for the faint hearted.  
The Army's first radar and decidedly crude by late WWII standards, non-the-less 
saw yeoman service in both the European and Pacific theaters of action.  We have 
one of those pieces of test equipment in our museum at Camp Evens and solicit 
leads to any other pieces of that venerable radar.
Ray  www.infoage.org

----- Original Message ----- From: "Christopher Bowne" <aj1g at sbcglobal.net>
To: <WA5CAB at cs.com>; <arc5 at mailman.qth.net>
Sent: Thursday, January 10, 2013 7:20 AM
Subject: Re: [ARC5] Link frequency meter


> Thanks Robert.  Yep - that appears to be the same unit, perhaps the chart
> provided in the "de-mil" version was changed from the original one, or there
> were several versions to work different frequency ranges.  I suspect that the
> one I have was dumped as a de-mil version after the war with a commercial name
> tag. The fifth harmonic of 39.1 Mc  (195.5 Mc) noted on my cal chart is at the
> low end of the frequency range quoted for the BC-438. Will have to put its
> variable output into my HP counter to see where its actually making its RF.
> Interesting that it is a piece of test gear for one of the very early radar
> systems.  The length of the little whip antenna appears to be close to a 
>quarter
> wave at 195-215 Mc.
> 
> 
> 
> 
> 
> ________________________________
> From: "WA5CAB at cs.com" <WA5CAB at cs.com>
> To: arc5 at mailman.qth.net
> Sent: Wed, January 9, 2013 3:12:58 PM
> Subject: Re: [ARC5] Link frequency meter
> 
> BC-438 was built for SCR-268 and covers 194-216 MC.  I had one once but
> sold it to a radar collector.
> 
> In a message dated 01/09/2013 13:19:59 PM Central Standard Time,
> elden_meyer at yahoo.com writes:
>> These are similar in principle to the BC-221 et al.
>> 
>> At least one version was made for the military, with a different frequency
>> range,
>> as the BC-438. There is a very brief description and schematic in the CQ
>> Surplus Schematics Handbook (on the Web various places). The diagram
>> should be similar for all models.
> 
> Robert Downs - Houston
> wa5cab dot com (Web Store)
> MVPA 9480
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