16 port? WTF? Are you military? Would be nice to see your antenna farm. Thats allot of connections.
Best RF Multi-coupler money can buy
- Thread starter blantonl
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I was comparing it as an pre-amp ahead of multicouplers--not a Stridesberg multicoupler. In my case, I am using a pre-amp ahead of the Stridesberg. Note the Strideberg does not have enough gain to improve S/N itself (but a pre-amp with low NF and more gain in front of it can if carefully done (filters etc).
I have not found a suitable low noise preamp that covers the entire range of interest to me 118 to 928MHz and has a high enough IP1/IP3 to survive without narrow band pass filters in front of it. So you give up some noise figure for higher IP1/IP3 and go with something like a ZHL-1010.
You can run a separate VHF air antenna with band pass filter and preamp, then a VHF hi antenna with filter and preamp then a UHF antenna with filter and preamp then a 700/800 antenna with filter and preamp then combine them all, which will reduce the chance of any preamp getting blitzed. A MiniCircuits ZX60-P103 could work for that up to 512MHz.
Or use a Discone for VHF air through UHF with an FM trap and preamp then combine with a 700/800 antenna filter and preamp. That sort of works here for me but needs a little upgrading after a new 5G tower went in and is bombarding me with enough signal at 700MHz to wreak my preamp.
You can run a separate VHF air antenna with band pass filter and preamp, then a VHF hi antenna with filter and preamp then a UHF antenna with filter and preamp then a 700/800 antenna with filter and preamp then combine them all, which will reduce the chance of any preamp getting blitzed. A MiniCircuits ZX60-P103 could work for that up to 512MHz.
Or use a Discone for VHF air through UHF with an FM trap and preamp then combine with a 700/800 antenna filter and preamp. That sort of works here for me but needs a little upgrading after a new 5G tower went in and is bombarding me with enough signal at 700MHz to wreak my preamp.
I've been re-doing my antenna system in my head for months and Lindsey drops big coin in a day....RR baller !
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Ill take the 225-400 thanks!
That is the better solution for my location/needs. Where I am lacking is a proper preamp and splitter, so this thread is what I needed. I have five various filters inline just for VHF/UHF RFI stuff, so I'll try the ZFL-2010 I am running my current setup with +10dB now.
* That K&L 5IZ10-20/x1300 diplexer is making it happen. Thanks for the heads up on that a few years back. One for home and one for portable use.
By the way, when you mount that double discone in your truck for the Cinco de Mayo parade, don't forget to add handlebar streamers on the elements.
No! I'll take the 225-400 amp. Slip that inline with my AT-197/GR and PAR 225-400 pass filter and I'm golden. I have dedicated scanners covering that range. He'll I'd also use that when portable with the AS-1404/PRC-41. Someone get Chip to come out of retirement and make some more of those.Ill take the 225-400 thanks!
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I do essentially as in your last paragraph with a 5G on 700 MHz about 2000 ft away that does not present a problem for me unless I get much closer (and then even without a pre-amp). Pre-amp I am using at the moment is this one https://rfbayinc.com/products_pdf/product_87.pdf
These are the parts I have on hand for my tower top 800/900 upgrade to get rid of 5G interference. The filter has a super sharp cutoff below 795MHz removing the big offender up the street that goes up to about 768MHz. The preamp has better specs than what I'm using now with .55dB NF and 19dBm IP1. These were surplused on Ebay in the $25-$30 range and I currently use a couple on my 900MHz amateur repeaters.
The little diplexer will replace a home made one using MiniCircuits high pass/low pass filters. Since I have transfer relays that will completely bypass all filtering and preamps giving a straight through path, the diplexer will give much better performance in bypass mode than the filters which interact some.
I previously swapped out a tiny Discone for an L-Com antenna that covers 824 to 960MHz with 6dBi gain. Its noticeably better than the Discone.
The little diplexer will replace a home made one using MiniCircuits high pass/low pass filters. Since I have transfer relays that will completely bypass all filtering and preamps giving a straight through path, the diplexer will give much better performance in bypass mode than the filters which interact some.
I previously swapped out a tiny Discone for an L-Com antenna that covers 824 to 960MHz with 6dBi gain. Its noticeably better than the Discone.
Yes, it's essentially a 43% discount off the discone. 🤣
I'm going to give the ANT280S shot and see how well it performs in the 768-881 MHz band as well as everything else between 118-900. My preference is to keep the amount of antennas I have deployed low, for... reasons. I currently have a 760-890 Yagi installed that is pointed south from my location to cover the primary public safety simulcast sites in my area, but I need better 770 MHz coverage for some northern stuff that I'm just on the cusp of.
If the ANT280S doesn't perform as well as I would like on 700/800 I might go for a dedicated 700/800 antenna on a diplexer with the ANT208S and the necessary filters.
The ANT280S is going to replace a DPD Productions OmniX Scanner Base Antenna - which has really treated me well and is extremely well built, but it has more directional characteristics than I would prefer and I've had to fiddle with it's orientation to compromise on some distant sites and VHF airband coverage. And, it might not even be a fault of the antenna, since I have a completely metal roof on my home.
I would be surprised if the radiation pattern of the ANT280S was consistent at the horizon over that much frequency range. I would suggest getting some baseline RX levels from it then temporarily swap with a 700/800 antenna of known gain, could even be a home made ground plane. If the Discone is working similar to a ground plane at 800 then its a winner. I did this and found my typical RS or D130 Discone was about 10dB worse at 800 than at 150 or 450Mhz. The gain is there but it points upward where its not useful so I only use the larger Discone for VHF/UHF then supplement with a dedicated 700/800/900 antenna and diplex them.
What I probably need to do is get a 769-860 MHz L-3 6db antenna and use that as a comparison.
But it doesn't appear that they have one that covers 700 and 800 MHz. Ideas?
But it doesn't appear that they have one that covers 700 and 800 MHz. Ideas?
It would also be REALLY nice if K&L made a high-pass filter like this that started at 768 MHz and up.
This is what my 700 MHz band looks like. LTE/5G doesn't seem to overwhelm what I've got but it's still pretty much a blast so I'm sure there's some impact.
This is what my 700 MHz band looks like. LTE/5G doesn't seem to overwhelm what I've got but it's still pretty much a blast so I'm sure there's some impact.
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I like the specs on the ZQLSC-1100 amplifier. The DB-9 connector threw me at first. I assume you are only using it to power it.
K&L will make any filter you want but their not cheap. Something like a 7 to 11 section high pass filter for 768MHz used to run about $600 in the 1990s, probably more now with a 6 week design and build time.
I use the DB9 for power and its a 24v rated amp, but you can lift the lid, jumper a diode and its a 12v amp.
Not to intrude on your conversation but from reading this thread, seems like 5G is going to be an issue for us scanners. Please elaborate.
For me everything in the 700/800/900 bands were good until some huge wide band signals showed up recently in the roughly 718 to 768MHz band. The carriers are about 10MHz wide each on my receivers spectral display. Today they are running about -30dBm on the spectral display and for a 10MHz wide carrier the peak power is much higher. I don't know the RBW of my receivers spectrum analyzer and will have to measure the exact levels on a real spectrum analyzer.
QUOTE="bearcatrp, post: 3627589, member: 53377"]
Not to intrude on your conversation but from reading this thread, seems like 5G is going to be an issue for us scanners. Please elaborate.
[/QUOTE]
QUOTE="bearcatrp, post: 3627589, member: 53377"]
Not to intrude on your conversation but from reading this thread, seems like 5G is going to be an issue for us scanners. Please elaborate.
[/QUOTE]
I'm pretty sure it's routed the other way....to avoid the need for an antenna farm.
Give me your thoughts on the Omni-X for VHF/UHF. I have to put mine up. I'm assuming the direction of the elements can cause some of its omni pattern getting shifted a bit, but wouldn't think it was not that significant.
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