[time-nuts] HP/Symmetricom 58535A and 58536A

J. L. Trantham jltran at worldnet.att.net
Sun Nov 1 13:36:31 UTC 2009


Said,

Interesting thought.  I had not considered the TBolt to be a source of a
problem.

I also have two HP 58517A 8 way splitters, one that gets it's DC for the
antenna through an SMB connector and one that gets it's DC from port 1.
They seem to work fine with the TBolt.  I also have a Symmetricom
090-58537-01 4 way splitter and it works fine with the TBolt as well.  By
this, I mean place the splitter between the TBolt and the antenna with
nothing else connected.

When I do this with the 58535A or 58536A, signal amplitudes, as noted on
TBoltMon, are divided in two with the 2 way splitter and non existent with
the 4 way splitter.  

I fired up my Z3816A, hooked it directly to the antenna and all was fine
with good signal amplitudes as noted on SatStat.  I then put the splitter in
the circuit and, again, all was fine.  I then hooked up the TBolt to another
port of the splitter and, now, it too is fine.  Seems it is all OK as long
as the Z3816A is connected.  I tried substituting a 50 ohm load on the ports
but the TBolt problem came back.  Might this be insufficient current for the
amplifier and antenna from the TBolt?  The 'Antenna Open' and 'Antenna
Short' indications on TBoltMon are fine no matter how or what is connected.

With the TBolt connected, I get about 4.5 VDC to the antenna from the
splitter.  I forgot to measure with the Z3816A connected.

Thanks for the insight.  My formerly thought dead splitters are, in fact,
fine.

I'll have to try adding an external supply to the splitter and see if that
fixes the problem.  Then, again, if just using the TBolt alone, why have a
splitter?  I guess the answer is that it is nice to have an easily available
connection for other projects.

Thanks again everyone for all the help.

Joe


-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of SAIDJACK at aol.com
Sent: Saturday, October 31, 2009 10:20 PM
To: time-nuts at febo.com
Subject: Re: [time-nuts] HP/Symmetricom 58535A and 58536A


Hi Joe,
 
I have the same problem with my Thunderbolt even though my splitter  works 
well. Not sure why. This is especially so if I cascade the Agilent unit  
with a passive splitter, I can never get the Thunderbolt to lock up.
 
I think the added noise of the Amp may play funny with the Thunderbolt's  
receiver, and there may not be anything wrong with your splitter.
 
M12M's and uBlox receiver's don't have a problem at all, even if two units  
are cascaded. They do start to have issues with three splitters in series.

Do you have another receiver you can try?
 
In terms of schematics, it's really straight forward, see the Mini-circuits 
 website for sample schematics for the ERA part, the agilent unit has  
pretty much the same setup.
 
The amp is followed by a resistive splitter, and possibly a resistive  
attenuator (on the 2-port version). Then a cavity filter, then the
N-Connector,  
very simple, not much that can go wrong.
 
bye,
Said
 
 
 
 
In a message dated 10/31/2009 18:21:16 Pacific Daylight Time,  
jltran at worldnet.att.net writes:

Said,

Thanks for the reply.  This is certainly a starting  point.  A schematic
would be wonderful.  I have looked and have  not found one yet.

The units both provide about 4.5 VDC to the center  pin when any port is
connected to my Tbolt.  However, the signal  amplitude, as measured by
TBoltMon, is essentially non existent on the 4  way splitter and divided by
at least 2 on the 2 way splitter.   Therefore, I suspect the amplifier is
dead.  Did not know about the  voltage regulator.  Will open one and get  to
work.

Thanks,

Joe

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