Icom FR4000 "noisy hollow pipe" sound, seems duplexer related?

[kayn1n32008]

I mean…I wouldn't buy a GTR8000 for conventional analog use as they can do some really weird things with analog. A Zetron MT-4E…I'd install all day long though.

You're never going to get a school to pop for a MT-4E, if it's a fight to get them to buy junk like your selling them.

Again, would help if dealers were hiring people who actually had the knowledge of equipment limitations…or if the guys getting ready to retire actually cared any longer.

I mean, they are spec'ing LMR400 and a mobile duplexer. The entire industry is filled with useless posers.

At the local club site, we are having to force a LMR dealer, who have clients that are our tenants, to upgrade their cabling in their multicoupler harnesses. One particular multicoupler is combining 2 repeaters onto a feedline with 6 ham repeater receivers past it. One of the cables in their multicoupler chain is slightly larger in diameter than RG174.

We, over the couse of the last 5 months, have found a metric **** ton of adaptors and LMR400 jumpers that aee getting replaced with RG400. One of the VHF ham repeaters was found to have 2 preamps in line, one after the other. Lots of neglect, and way too many I competent people in positions of power that have zero business building rf systems that combine multiple repeaters to single or community antennas. Over the last 10 years shot was just stabbed together with zero care, zero planning and not enough knowledge of how to do it.

We won't even get into the issue of licensing that was never updated to reflect the new location, or the change in antenna height and system losses, or the unlicensed repeater the have on the air. Yes the club bears responsibility in allowing this to be done, but the dealer is the SME.

Back to the issue at hand. I'd do a license search, including cellular, with a radius of 500m and do an IM study of what you find. I saw mention that there was nothing with in 10Mhz, but if it's a mix product, 10MHz span just isn't going to cut it.

 

[Project25_MASTR]

You're never going to get a school to pop for a MT-4E, if it's a fight to get them to buy junk like your selling them.

I mean, they are spec'ing LMR400 and a mobile duplexer. The entire industry is filled with useless posers.

At the local club site, we are having to force a LMR dealer, who have clients that are our tenants, to upgrade their cabling in their multicoupler harnesses. One particular multicoupler is combining 2 repeaters onto a feedline with 6 ham repeater receivers past it. One of the cables in their multicoupler chain is slightly larger in diameter than RG174.

We, over the couse of the last 5 months, have found a metric **** ton of adaptors and LMR400 jumpers that aee getting replaced with RG400. One of the VHF ham repeaters was found to have 2 preamps in line, one after the other. Lots of neglect, and way too many I competent people in positions of power that have zero business building rf systems that combine multiple repeaters to single or community antennas. Over the last 10 years shot was just stabbed together with zero care, zero planning and not enough knowledge of how to do it.

We won't even get into the issue of licensing that was never updated to reflect the new location, or the change in antenna height and system losses, or the unlicensed repeater the have on the air. Yes the club bears responsibility in allowing this to be done, but the dealer is the SME.

Back to the issue at hand. I'd do a license search, including cellular, with a radius of 500m and do an IM study of what you find. I saw mention that there was nothing with in 10Mhz, but if it's a mix product, 10MHz span just isn't going to cut it.

It probably doesn't help that sales folks see the mobile duplexers for a SLR5700 as the accessory from Motorola when ordering.

I'm dealing with stuff like that at my sites though too. The paging system is based off of TKR-750's and relies on the dispatchers multi-selecting, repeaters using the same inputs with different outputs and even a couple of cascaded repeaters. It's a mess and over the years the local dealer (the bear) has kept it operational with bare minimum fixes (but their bills make it look like they are doing serious work). I'm replacing it all next year…and getting rid of the multi-select and cascading but LMR is everywhere (wasn't originally but it is now), things are highly questionable and several of the fire chiefs in the county are convinced they need 300W PA's on those repeaters to make them work on their pagers. There are more paging sites at 150W and 300W in the county than trunking sites (all of it is VHF too).

 

[kayn1n32008]

It probably doesn't help that sales folks see the mobile duplexers for a SLR5700 as the accessory from Motorola when ordering.

You are right. It doesn't help at all.

It's a mess and over the years the local dealer (the bear) has kept it operational with bare minimum fixes (but their bills make it look like they are doing serious work).

The sooner you get that customer out of their greedy, grubby hands, the better off the customer will be. I know EXACTLY what you are talking about. I've heard stories of their handy work where I live.

I'm replacing it all next year…and getting rid of the multi-select and cascading but LMR is everywhere (wasn't originally but it is now), things are highly questionable and several of the fire chiefs in the county are convinced they need 300W PA's on those repeaters to make them work on their pagers. There are more paging sites at 150W and 300W in the county than trunking sites (all of it is VHF too).

Sounds like a nightmare. Good luck.

 

[ElroyJetson]

I'm seeing that the medium term future of communications in schools is going to probably end up being wifi based radio applications. It's already happening in some schools and they're only going to get better and better at this emerging technology.