Need some feedback on this setup: Wanting to setup a GMRS base station. Was going for the Midland MXT400 and a Browning 450-470MHz Omni Base Antenna. Connecting the two with 100ft of RG8x Coax.
100 feet of RG-8X isn't a very good choice.Connecting the two with 100ft of RG8x Coax.
just a question - would it do any good to use 2 different cables ? I am getting ready to do an outside antenna. When building we had conduit installed that goes out thru the concrete floor, under the footings and will come up alongside where a antenna structure will be. So in order to get the cable(s) thru the conduit would it make any sense to use something like 8x from the radios, out the conduit then switch to something better for 50 - 75 feet up to the antenna ?100 feet of RG-8X isn't a very good choice.
40 watts out of the radio will suffer a LOT of loss over that length of cable. Of the 40 watts you put in, less than 6 watts will make it to the antenna. That is 8.4dB of loss. Same works on the receive side, you'll lose a lot of your received signal due to coax losses.
Two options:
Greatly reduce the amount of cable between your radio and antenna.
If that is not an option,
Use a higher grade cable. LMR-400, LMR-600 or 1/2 inch Heliax for a 100 foot run. That'll give your transmitted and received signal a chance. Problem is, those are going to be more expensive and harder to install.
That is a reasonable solution if it's a short run.just a question - would it do any good to use 2 different cables ? I am getting ready to do an outside antenna. When building we had conduit installed that goes out thru the concrete floor, under the footings and will come up alongside where a antenna structure will be. So in order to get the cable(s) thru the conduit would it make any sense to use something like 8x from the radios, out the conduit then switch to something better for 50 - 75 feet up to the antenna ?
If is a completely stupid idea - feel free to say so
Conduit was a necessity for access to the location - room is secure, solid concrete all the way around - so conduit was installed thru the floor, underground and underneath the building's footing and back up above grade outside the wall. Conduits are 2 inch pvc and were planned properly - just as in any project one in place and operational always something to add on. Total conduit length is only about 10 - 12 feet. In my case and considering adding some additional antennas for scanner, maybe even a CB antenna just for fun, a WiFi antenna, perhaps a dedicated antenna for MURSThat is a reasonable solution if it's a short run.
Issues I'd be concerned about:
1. Any conduit below grade -WILL- collect water. You need to be sure the coax will handle that. Filled/direct bury rated cable can solve that issue, but there can be fire code issues running some of those cables indoors for too far a distance.
2. RG-8x is a pretty low grade cable. Doesn't make sense to use it in any sort of commercial application. There are -much- better cables.
3. Consider the added losses of the connections you'll be adding. Coax connectors are not lossless connections.
If the conduit is undersized, that's a design issue. RG-8x is "radio shack grade" cable, not really that good for much else than cb radio use. Not suitable for long runs at higher frequencies. If you have put the effort into conduit and a 50 to 75 foot antenna support, don't cripple the system with low grade coax. Something like LMR-240 is a similar size and has better performance.
If it's electrical PVC with sweep 90º's, fitting a few LMR400 runs in there shouldn't be an issue. Just pull them all in at once.Conduits are 2 inch pvc
I would use LMR-600 if you can. If you can afford it, use Heliax. And that Browning antenna is unity gain. Since you're going to all the trouble, get something with 6dbd (8dbi) gain at least. That will make your 40w radiate as 160w ERP. That Comet would be sufficient.Was going for the Midland MXT400 and a Browning 450-470MHz Omni Base Antenna. Connecting the two with 100ft of RG8x Coax.
If it's working, that's good.with 50 ft of RG58
I'll also point out that this antenna is a dual band amateur radio antenna. On the UHF side it's designed to work in the 430-450MHz range. That's impacting your performance also. Again, if it's working for you and you are happy, no problem, but make sure you check the SWR.to a Tram 1485 antenna