Multicouplers

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w4rtt

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Once upon a time, I too thought I needed a Stridesberg, so I shelled out the big bucks.
Then I decided to try something else. I found these on eBay; Celwave PD861C 6 Way Power Splitter 806 825MHz | eBay

At the time I got mine, he advertised them as being swept with an analyzer and useable down to 100mhz. For $10, it was worth a chance. Comparing side by side with an Icom R8500, the signal quality was virtually the same. Scrounged around an got a couple Minicircuits amplifiers. Finally settled on this one; Mini Circuits ZFL 1000 Amplifier 0 1 to 1000MHz Gain 18nu ll Po9D BM15V | eBay
These can be had for half this if you look around. I think I paid all of $15 for mine.

So, for $25, I had another $300 Stridesberg.
 

737mech

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Once upon a time, I too thought I needed a Stridesberg, so I shelled out the big bucks.
Then I decided to try something else. I found these on eBay; Celwave PD861C 6 Way Power Splitter 806 825MHz | eBay

At the time I got mine, he advertised them as being swept with an analyzer and useable down to 100mhz. For $10, it was worth a chance. Comparing side by side with an Icom R8500, the signal quality was virtually the same. Scrounged around an got a couple Minicircuits amplifiers. Finally settled on this one; Mini Circuits ZFL 1000 Amplifier 0 1 to 1000MHz Gain 18nu ll Po9D BM15V | eBay
These can be had for half this if you look around. I think I paid all of $15 for mine.

So, for $25, I had another $300 Stridesberg.

That's awesome! I have a few questions for ya, do you have any tech specs on that splitter for port to port isolation or db loss from input to output? Those are some of the things that people with scanners look for in a splitter. I'm assuming there is a loss because you felt the need to add a minicircuits amp to the mix? Does it really do well in the lower bands? How about your setup and area, are you out and away from a city with tons of cell phone towers? What kind of scanner, antenna and coax? All these things really help us understand the big picture you are trying to make us aware of. These splitters seem very cost effective and exactly what people with many scanners and one antenna want. However alot of people read the specs and the forums for every last detail before they make a decision to buy. I respect the membership of these forums and understand many are very highly educated and will probably comment about this splitter before I submit this post. So I guess I'm saying you have my attention but please give us some more details and results from your setup with this equipment ok?
 

w4rtt

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I emailed the seller and he didn't have any specs on the multicouplers.
Given my location, I;'m always looking for an edge on vhf/uhf. I had a couple Minicircuits on hand. There was only about half an S unit loss without the amp. With the amp, the was around 5 S unit gain on selected NOAA transmitters.
I am in a rural setting with no cell or pagers to contend with. I am within eyesight ot the county PD and FD transmitters, so I get splatter from them without the amp inline.
Nothing in the area to compare on vhf/lo band around here.
The antenna it is used on is a Niljon Super M at around 30ft, fed with LMR400 coax.
 

w4rtt

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Hooked this multicoupler to my Yaesu and the T@FD and checked around MW and HF. No noticeable loss at any frequency.
 

dimab

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I've been struggling with the idea of paying $200 for the stridesburg. Just ordered one of these. Hoping it works 90% of what the stridesburg will do.
 

prcguy

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So, for $25, I had another $300 Stridesberg.

Well, not really.

The Stridesberg MCA204M has a noise figure of 3.5dB but the MiniCircuits ZLA1000 has a noise figure of 6dB, not so good. The Stridesberg 1dB compression is +17dBm with an IP3 of +31dBm, not great for a system front end but they seem to work. The ZFL-1000 has a 1dB compression of +9dBm and an IP3 of +18dBm, that's really not something I would want connected to a wide band antenna with no preselection. I have a bunch of ZFL-1000s, ZFL-2500s, etc and would never consider them for a front end preamp.

Then there is the divider itself which is a narrow band, probably Wilkinson divider which will have very nice isolation and through loss within its design range but outside its no more than a big "T" adapter with no isolation, no impedance matching between ports and more loss. You would probably get better performance from a cheap amplified CATV splitter since its designed for wide band.

Bottom line - unless you have some RF design experience or happen across a suitable wide band divider and amplifier you will not get anything close to to the Stridesberg or what would be considered acceptable performance.
prcguy
 

737mech

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Celwave Splitter

I agree with you PRCGUY but I also like my Electroline. Just for curiosity I bought one of these Celwave splitters 1 to 8 way and opened it up. I should post a pic of the guts but really no need there's not much there, bnc connectors and mostly direct connects to the other ports on a circuit board. No isolation port to port. Might be a real problem with 8 scanners hooked up. I did not bother to try it. No disrespect to the OP if it works for you great! But my advise to the OP, there is a real difference having many scanners sharing one antenna with a good splitter and I will add after reading many of the posts from PRCGUY he really knows what he's talking about.
 

dimab

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I received my unit and installed. It works. Lost 1-2 bars on the S-meter across most frequencies.

Based on my non-scientific observations, it def. loses signal. I have it going to 4 scanners, and all seem to be working just fine. No strange noises as sometimes described when using a BNC T connector. Some channels are now noisier than before, and some of the trunked sites I monitor are now out of reach (other sites are filling in). For my setup, I'm pretty happy with this $10 gadget.

My setup:
RS discone on the roof. 25' run of RG8X into a preamp, and another 25' of RG8X into the multicoupler.
Connects to a BCT15, BCD996T, BC350C, and a NooElec SDR

shot_11252013_104725_am.png
 

w4rtt

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Independence, KY
Well, not really.

The Stridesberg MCA204M has a noise figure of 3.5dB but the MiniCircuits ZLA1000 has a noise figure of 6dB, not so good. The Stridesberg 1dB compression is +17dBm with an IP3 of +31dBm, not great for a system front end but they seem to work. The ZFL-1000 has a 1dB compression of +9dBm and an IP3 of +18dBm, that's really not something I would want connected to a wide band antenna with no preselection. I have a bunch of ZFL-1000s, ZFL-2500s, etc and would never consider them for a front end preamp.

Then there is the divider itself which is a narrow band, probably Wilkinson divider which will have very nice isolation and through loss within its design range but outside its no more than a big "T" adapter with no isolation, no impedance matching between ports and more loss. You would probably get better performance from a cheap amplified CATV splitter since its designed for wide band.

Bottom line - unless you have some RF design experience or happen across a suitable wide band divider and amplifier you will not get anything close to to the Stridesberg or what would be considered acceptable performance.
prcguy


Well, I actually have the parts in hand and in use. There sure isn't $275 more in value with the Stridesburg. As I stated in the original post, the multicoupler was swept with an anylizer and shown to be effective down to 100mhz. I should have stated that I use tuned antennas for each band.
Numbers are good. You can make them say anything you want. Too much emphasis placed on them for scanner listening. I can live with an S unit difference. Bottom line for me, the parts work well together, and I can put the money on something like a new radio.

Randy
 

w4rtt

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May 7, 2010
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Location
Independence, KY
I received my unit and installed. It works. Lost 1-2 bars on the S-meter across most frequencies.

Based on my non-scientific observations, it def. loses signal. I have it going to 4 scanners, and all seem to be working just fine. No strange noises as sometimes described when using a BNC T connector. Some channels are now noisier than before, and some of the trunked sites I monitor are now out of reach (other sites are filling in). For my setup, I'm pretty happy with this $10 gadget.

My setup:
RS discone on the roof. 25' run of RG8X into a preamp, and another 25' of RG8X into the multicoupler.
Connects to a BCT15, BCD996T, BC350C, and a NooElec SDR

shot_11252013_104725_am.png

Thanks for the reasonable evaluation.
 

w4rtt

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Messages
174
Location
Independence, KY
I agree with you PRCGUY but I also like my Electroline. Just for curiosity I bought one of these Celwave splitters 1 to 8 way and opened it up. I should post a pic of the guts but really no need there's not much there, bnc connectors and mostly direct connects to the other ports on a circuit board. No isolation port to port. Might be a real problem with 8 scanners hooked up. I did not bother to try it. No disrespect to the OP if it works for you great! But my advise to the OP, there is a real difference having many scanners sharing one antenna with a good splitter and I will add after reading many of the posts from PRCGUY he really knows what he's talking about.


No disrespect taken, but if you didn't bother to try it, then you really don't know how it works. I do have one hooked to 8 different scanners, and there is no interference and minimal signal loss. I don't have certificates on the wall or education degrees, just 40 yrs of listening experience. Just trying to present a different point of view and save people some money.
 

dimab

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Dec 19, 2002
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Location
CT
I started decoding ADSB data, and at 1090MHz this multicoupler is a total bummer. I may make another run of RG8X to the roof with a second antenna for this project.
 
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