[time-nuts] GPS antenna splitter recommendation?

[Bob kb8tq]

Hi

Again, that’s just the candidates pulled out of the first dozen.  

Three port splitters (in general) don’t exist. At least not on the “low cost” end
of things. You either use a 4 or a set of three 2 ports ( to make a 4 port). 

Each time you split 2 ways, you “loose” 3 db ( equal power into two loads). A two way
will be 3 db and a 4 way 6 db. Yes, there is some fraction of a db that is truly lost and 
not just split between the loads. Figure 0.1 db or check the spec sheet on the Mini
Circuits web site if you really need to be accurate. 

With some shopping ( = going through all 200 or 500 listings), you should be able to find
something reasonable for < $30 delivered. I’d go for something up around 8 ports or so.
GPS stuff tends to multiply …. 

Maybe this one if the guy will take a $20 offer:

https://www.ebay.com/itm/Mini-Circuits-8-Port-IF-Splitter-Combiner-15542-ZB8PD-2/182003853838?epid=1529816498&hash=item2a60466a0e:g:vzcAAOSwqYBWpoFo <https://www.ebay.com/itm/Mini-Circuits-8-Port-IF-Splitter-Combiner-15542-ZB8PD-2/182003853838?epid=1529816498&hash=item2a60466a0e:g:vzcAAOSwqYBWpoFo>

It will have 3 db more loss than a 4 way (so a total of 9 db). 

At some point your combo of loss in the splitter, loss in the coax from the antenna, loss in the cable 
from the splitter to the GPS is more than the device can handle. Figure that you need about 12 db
“left over” even for a fairly good device. People do make GPS amps if you go to far.

Bob


> On Apr 29, 2020, at 10:06 PM, Frank O'Donnell <time at inkbox.net> wrote:
> 
> On 4/29/20 6:01 PM, Bob kb8tq wrote:
>> Here’s a few:
> 
> Bob, thanks very much for the suggestions.
> 
> Five of the seven splitters in your list appear to offer a total of two output ports. What I'm looking for is one that will accommodate (specifically) three or four ports.
> 
> Of the remaining two on the list, this one:
> 
>> https://www.ebay.com/itm/Mini-Circuits-ZN4PD1-63W-S-RF-Power-Splitter-250-6000MHz-Qty-Available-GOOD/133387795141?hash=item1f0e883ac5:g:tdoAAOSwAbxel2o~ <https://www.ebay.com/itm/Mini-Circuits-ZN4PD1-63W-S-RF-Power-Splitter-250-6000MHz-Qty-Available-GOOD/133387795141?hash=item1f0e883ac5:g:tdoAAOSwAbxel2o~>
> 
> has five outputs and costs $50. Probably usable, though I was wondering if going with additional output ports could increase possible loss? And also, the price isn't a show-stopper but is a little high for what I was hoping for.
> 
> The other one:
> 
>> https://www.ebay.com/itm/New-Mini-Circuits-ZB6PD-2-S-800-2000-MHz-Power-Splitter/114155096838?hash=item1a942c8b06:g:jNIAAOSwedNedT92 <https://www.ebay.com/itm/New-Mini-Circuits-ZB6PD-2-S-800-2000-MHz-Power-Splitter/114155096838?hash=item1a942c8b06:g:jNIAAOSwedNedT92>
> 
> isn't entirely clear to me. The text says it's a three-port, but I count four visible connectors that look like output ports, and two more that might be hiding under caps. This one goes for $19.90.
> 
> Given all of that, do either of these two seem like the optimal way to go if I want to plug in three or four GPSDO's?
> 
> Thanks again,
> 
> Frank
> 
> 
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