source 950 combiner

Gotta watch those Fresnel zones!
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TPT
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Joined: Mon Dec 03, 2007 3:18 pm
Location: St. Marys, WV

source 950 combiner

Post by TPT »

Adding station-need 2nd STL. Need a combiner for the two STl's as eventually the STL antenna will be on the AM tower for the second station (the 2nd STL will be for the associated translator). 949.0 and 946.375

Suggestions on brand /source? Of course, we are only talking about ten watts from each transmitter.
jammerdave
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Re: source 950 combiner

Post by jammerdave »

DaveSt
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Location: UK

Re: source 950 combiner

Post by DaveSt »

TPT wrote: Tue Aug 04, 2020 8:52 am Adding station-need 2nd STL. Need a combiner for the two STl's as eventually the STL antenna will be on the AM tower for the second station (the 2nd STL will be for the associated translator). 949.0 and 946.375

Suggestions on brand /source? Of course, we are only talking about ten watts from each transmitter.
It will be difficult with that frequency spacing. I do not know of anyone that has a combiner that could do that.
ncradioeng
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Joined: Wed Nov 18, 2015 3:58 pm

Re: source 950 combiner

Post by ncradioeng »

Marti used to make a combiner for their dual-mono STLs if you can find one. It's basically a directional coupler with a small reject load. Half the power goes to the antenna and the other half to the load for each transmitter so it's lossy but should handle the frequency split.
ChuckG
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Re: source 950 combiner

Post by ChuckG »

http://microwavefilter.com.s3-website-u ... biners.htm

Those are the only ones I know of outside finding one of the Marti HRC-10's used somewhere.
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DaveSt
Posts: 64
Joined: Mon Jul 23, 2018 2:21 pm
Location: UK

Re: source 950 combiner

Post by DaveSt »

The Marti and MFC use 3db couplers and presumably circulators too. They will work so long as you can afford to burn more than half of the transmitter powers. So long as the link is not marginal that should be fine and you can always make it up with antenna gain if needed.
TPT
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Joined: Mon Dec 03, 2007 3:18 pm
Location: St. Marys, WV

Re: source 950 combiner

Post by TPT »

The path is quite short, just over two miles. At the top of the 60' STL tower, can see the FM tower. Most of the loss is in the cable run--around 200 feet, using 7/8th now. Plan on using that cable for the BE-1A when it is moved. If the combiner price is reasonable will just get two more lengths of 7/8 made up, mount the stl antenna back up at 60' when the new AM tower goes up, then the only additional loss will be in the isocoupler.

I'll give Microwave Filter a call. Have dealt with them in the past.
DaveSt
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Joined: Mon Jul 23, 2018 2:21 pm
Location: UK

Re: source 950 combiner

Post by DaveSt »

There would be something seriously wrong if you could not get that working with a watt!
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