How well do these splitters work?

[WayneH]

Ever hear of birdies? Spurious signals generated by digital electronics? You need to isolate two or more receivers so they don't interfere with each other. The port isolation of a Drop Amp does this, weak signal or not.

So what about taking in to account the port-to-port isolation of the output ports for any standard CATV splitter, same thing. I think for the most part it's not much of a worry.

But back to the OP....
I run the Stridsburg 4-port with one port split with a BNC T. Since the radios off the T are dedicated to certain systems with strong enough signal I don't have to worry about the loss. So that's an alternative if you forego the worries of isolation.

 

[hvscan]

Wirelessly posted (BlackBerry9530/5.0.0.328 Profile/MIDP-2.1 Configuration/CLDC-1.1 VendorID/105)

Just put an Electroline 2802 into service. So far, so good. I am pleased with the combined reception I am receiving. Time will tell for sure, as to whether this is a good substitute for a multi coupler for my use, but I do like it so far.

 

[tonsoffun]

Wirelessly posted (BlackBerry9530/5.0.0.328 Profile/MIDP-2.1 Configuration/CLDC-1.1 VendorID/105)

Just put an Electroline 2802 into service. So far, so good. I am pleased with the combined reception I am receiving. Time will tell for sure, as to whether this is a good substitute for a multi coupler for my use, but I do like it so far.

You will be very happy with the Electroline's. I have two of them in service to feed the bearcats!

 

[hvscan]

Wirelessly posted (BlackBerry9530/5.0.0.328 Profile/MIDP-2.1 Configuration/CLDC-1.1 VendorID/105)

Thanks Tons...already scouting out a 2nd one. You can't beat the price.

 

[jackj]

Isolation

So what about taking in to account the port-to-port isolation of the output ports for any standard CATV splitter, same thing. I think for the most part it's not much of a worry.

But back to the OP....
I run the Stridsburg 4-port with one port split with a BNC T. Since the radios off the T are dedicated to certain systems with strong enough signal I don't have to worry about the loss. So that's an alternative if you forego the worries of isolation.

Yes, there is some isolation using a cheap splitter. There will be around 6 - 7 db of port-to-port isolation. That isn't usually enough to eliminate interference generated by the other radio. There is another option, spend several hundred dollars on a 2-port directional coupler.

 

[ronhl]

I measured the loss of an SP-1300 splitter using a Agilent Network Analyzer, so all can see.
insertion loss (db)
Freq (mhz input - out A output B terminated into 50 ohms
30 -3.9
40 -3.9
50 -3.9
120 -3.8
140 -3.8
150 -3.8
160 -3.8
170 -3.9
200 -3.9
240 -4
300 -4.1
400 -4.4
450 -4.5
480 -4.6
512 -4.6
600 -4.9
700 -5.3
800 -5.7
850 -6.1
900 -6.2
950 -6.7
1000 -6.9
1100 -7.8
1200 -9
1300 -10

 

[N_Jay]

Was the "input" terminated?

 

[jackj]

The network analyzer should terminate both ports at whatever impedance is selected.

 

[N_Jay]

The network analyzer should terminate both ports at whatever impedance is selected.

Except there are three ports on a 2 way splitter.:roll:

 

[jackj]

My goodness N_jay, you caught me on that one. I completely missed the part where he stated that port B was terminated. You know, this part:

"Freq (mhz input - out A output B terminated into 50 ohms"

I wonder if ronhl could be talked into running that test again, this time from Port A to Port B with the input terminated. That should give the port to port isolation. In any case, thank you for taking the time to run the test. It kind of looks like the splitter might be a ferrite core transformer instead of resistors.

 

[ronhl]

sp-1300 out-out isolation input into 50 load

freq:
50 = -29.4db
150 = -24.5
220 = -21.5
400 = -17.8
450 = -17.5
700 = -17.5
850 = -18.8
1300 = -13.8

 

[jackj]

Thanks ronhl, that is MUCH better than I would have expected.

 

[lmrtek]

A 99 cent 2-way tv splitter would likely do equally well since most passs 5-1000mhz with 3.5db loss per port

A receiver multi-coupler with a broadband preamp ahead of it would be the optimum situation but
with only 2 scanners, you will likely not need that level.

 

[prcguy]

Look at the test data in a previous post, these splitters reach 4.5dB loss at 450MHz and 6dB loss at 850MHz, not so good.
prcguy

A 99 cent 2-way tv splitter would likely do equally well since most passs 5-1000mhz with 3.5db loss per port

A receiver multi-coupler with a broadband preamp ahead of it would be the optimum situation but
with only 2 scanners, you will likely not need that level.

 

[N_Jay]

Look at the test data in a previous post, these splitters reach 4.5dB loss at 450MHz and 6dB loss at 850MHz, not so good.
prcguy

If the third port was not terminated, the measurements are not reliable.

 

[ronhl]

sp-1300

If the third port was not terminated, the measurements are not reliable.

All my measurements were taken with the unused 3rd port terminated into 50ohms as I CLEARLY indicated.

 

[N_Jay]

mY bRAIN fART!

Feel free to make derogatory statements about my ability to read.

 

[zguy1243]

I have both the Stridsberg 4 port and the Scientific Atlanta 4 port active drop amp. Would anyone be interested in a video comparing the two? There is a difference in the amps. I can say that in the 225-400Mhz range the Scientific Atlanta 4 port models are better performers than the Strigsberg 4 port active.

 

[mrkelso]

I got this one coming in next week.