[time-nuts] 58536A splitter and 9390-6000 GPS

[Ed Palmer]

I have a 58536A.  Although it isn't mentioned in the datasheet or 
manual, mine has a DC load on each input.  The load is four 1330 ohm 
surface mount resistors in parallel, e.g. 332 ohms or about 15 ma @ 5 volts.

Ed

Robert Watzlavick.com wrote:
> I thought the 58536A was supposed to provide a load to the other receivers for that reason. But now that I look at the datasheet more closely, that feature may only be available for the 58537. 
>
>   
> -Bon
>
> On May 20, 2011, at 7:25 AM, paul swed <paulswedb at gmail.com> wrote:
>
>   
>> It may need a resistor to ground something that draws 5-10ma. Some GPS rcvrs
>> need the dc load to believe a antenna is attached.
>>
>> On Fri, May 20, 2011 at 7:21 AM, Robert Watzlavick <rocket at watzlavick.com>wrote:
>>
>>     
>>> On 05/19/2011 10:35 PM, WB6BNQ wrote:
>>>
>>>       
>>>> Robert,
>>>>
>>>> Two questions.
>>>>
>>>> First, what is the voltage at the 9390 antenna connector with nothing
>>>> attached
>>>> besides your DVM ?
>>>>
>>>> It shows 5V open circuit.
>>>>         
>>> Second, what happens if you just attach the antenna straight to the 9390 ?
>>>       
>>>> By
>>>> this i mean if voltage is on the antenna connector and while you are
>>>> observing it
>>>> and then attach the antenna what happens ?
>>>>
>>>> I found something interesting here - with it connected straight to the
>>>>         
>>> antenna, I measured 4.6V.  I connected and disconnected it several times and
>>> didn't see any drops.  But, after the 5th connection or so, I finally got
>>> the 9390 to show the same behavior as with the splitter and shut off its
>>> antenna supply.  So it seems it's not exclusive to the splitter but just
>>> that it occurs more often.  The antenna is connected directly to the little
>>> GPS daughterboard module and I don't have schematics for it.
>>>
>>> This isn't a showstopper, just interesting behavior.  One of the things I
>>> like about the 58536A is that it will continue to power the antenna if you
>>> remove other receivers from the ports (for troubleshooting etc.)  I guess
>>> with this particular receiver, it is a little more sensitive to antenna
>>> disconnects while it is powered on.
>>>
>>> I suspect there is some protection process with the 9390 and the load or
>>>       
>>>> reverse
>>>> voltage present from the splitter is causing it to activate.  However, I
>>>> am not
>>>> familiar with that unit.  Just asking general troubleshooting questions.
>>>>
>>>> Bill....WB6BNQ
>>>>
>>>> Agree - thanks.
>>>>         
>>> -Bob
>>>