[time-nuts] Partridge Divider Board

[Gordon Batey]

Greetings to the TimeKeepers,

I appreciate the comments on the Partridge Divider board.  I am also seeking
an enclosure and your comments have some interest for me.  

I would also be interested in any comments regarding a source of input and
output connectors for this project.  The board is designed for SMA vertical
connectors which I have found at about $10 each.  Pretty steep for me.  I
would prefer right angle, threaded BNC connectors similar to those used in
the TAPR distribution box but I have not found any of these that appear to
be suitable.  Any suggestions are appreciated.  

73 Gordon WA4FJC
GPBATEY at wildblue.net

====================================================================


Date: Sun, 27 Feb 2011 20:35:33 EST
From: Brucekareen at aol.com
Subject: [time-nuts] Partridge Divider Board and 10 MHz Distribution
	Amplifier Enclosure -- an Idea
To: time-nuts at febo.com
Message-ID: <173ea2.5175575.3a9c55e5 at aol.com>
Content-Type: text/plain; charset="US-ASCII"

While admiring my newly received divider board from David Partridge and  
thinking about a suitable enclosure for its use on my bench, I happened to 
look  at an Extron ADA3 80 video distribution amplifier that I acquired
after  
suggestions from KO4BB.  These enclosures are mechanically sturdy and quite

empty on the inside.  There is plenty of room to mount the divider board  
if existing (unused) threaded standoffs are relocated to match the  divider 
board mounting holes.  As the distribution amplifier's circuit  board and 
connections are all on the back panel, the front panel is completely  free
and 
clear for mounting the division ratio switch and output  connectors.  
 
The analog performance of the distribution amplifier seems very good;  
however, the BNC output connectors are grounded to the case and there is
only  
one active output device for each of the R, G, & B outputs.  The  three 
output connectors provided for each are simply isolated through resistors,
thus 
isolation is limited.  Nevertheless, for a single bench setup  like mine, 
the distribution amplifier will probably serve adequately well to
distribute 
10 MHz from a T-bolt to the counters, divider board, and a  signal generator

-- all on the same bench.  As the R, G, & B DA  inputs can be looped, the 
ADA3 80 can provide up to nine 10 MHz outputs   via BNC connectors.
 
The ADA3 80 is powered from an external 9-volt, 500 ma wall wart.   
According to KO4BB:  _http://www.ko4bb.com/Timing/Distribution_Amp/_ 
(http://www.ko4bb.com/Timing/Distribution_Amp/) ,  the DA has an onboard
switching 
converter and + and -5 volt regulators to power  the distribution
amplifiers.  It 
is possible there is sufficient +5 volt  current capacity to power the 
divider board too.  I have not investigated  this yet as I am not certain
about 
the maximum current requirement for the  divider board.  Assuming it can be 
powered from the existing supply, one  could wind up with a very nice and 
compact bench frequency reference and  distribution system.  
 
Extron rates the power consumption of the ADA3 80 at 2-watts.   However, it 
appears Extron uses the same PC board and power unit for the ADA3  180 for 
which the power consumption is 3-watts. 
Thus there may be adequate capacity to safely power the divider  board.  
 
If power supply noise is a problem, there is plenty of room in the case for 
 additional filtering.
 
Bruce Hunter, KG6OJI