Quantar Installation Tips

[kt2728]

I am getting ready to install my new Quantar on a tower with a high power FM broadcast station. It is a VHF repeater i plan on running in mixed mode operation. I am looking for any tips or advice for this type of installation. the site is atop a mountain (a 1200 FT rock out here on the plains) and is accessible only by foot or helicopter. I have lined up a helicopter for the initial install. I want to do this right the first time so i do not have to hike up and down this mountain once i get it on the air.

any advice or tips are welcome

kt

[N4DES]

Is this a total new installation (duplexer, antenna, etc.)?

I would highly reccomend not installing any kind of pre-amp.
Use the highest quality cable you can find like 1/2" hardline or 1/4" superflex.
Be sure to ground everything together to whatever central ground point there is in the building.
If you can, do a temporary installation on the gorund first to burn everything in for at least 2 weeks to make sure everything plays together in harmony.

That's my 2 cents worth...
Mark

[kt2728]

Mark thanks for the reply.

why do you not recommend a pre amp?

i am not planing on using one, just curious.

i do have a temporary installation point work the bugs out, i am hoping to get it installed there within the next couple of weeks.

Battery backup i would like to hear some recommendations on them also. i am assuming i should use some sort of lead acid, but i dont know that is why i am asking here.

[W6WAW]

Just a comment on the battery issue.

There are a number of ways to do it. For a start, I suggest searching the batboard using terms like "Quantar battery revert" and "Quantar battery backup" because there have been numerous postings by people who know a lot about the various alternatives.

Some of your options will turn upon whether your power supply supports battery revert, and if so whether you want to use it or something else.

Regardless of the method you chose, one important thing is to buy the best deep cycle batteries you can afford -- such as good quality AGM or other sealed units. There's a saying that paying for quality only hurts once and that is especially true of batteries which will be located at a hard to reach site.

Good luck with your project.

Fred

[Bill_G]

On the preamp - I wouldn't recommend one either for a VHF station at a FM broadcast site without doing a site noise floor study. The broadcaster(s) may be running legal, but with so much local energy on top of the receiver, their xmit noise may put your threshold at -100db. If the site has excellent grounding, if the broadcaster has excellent filtering, and if you have excellent filtering, you may be able to get the floor down to -105db or even -110db. But, don't expect it to be quiet enough for a preamp to operate successfully without getting swamped.

[qball]

KT,

The common sense things, of course....

Pre-assemble and test every cable, power connection, filter, station settings...the works.

I re-tuned a mixed-mode Quantar yesterday that had drifted +3.8K from when the new P25 SCM was installed a month ago. The repeater still repeated everything, but was out of spec enough that the XTS2500s subscribers would not unmute.

Good luck with the installation!

Q

[N4DES]

On the preamp - I wouldn't recommend one either for a VHF station at a FM broadcast site without doing a site noise floor study. The broadcaster(s) may be running legal, but with so much local energy on top of the receiver, their xmit noise may put your threshold at -100db. If the site has excellent grounding, if the broadcaster has excellent filtering, and if you have excellent filtering, you may be able to get the floor down to -105db or even -110db. But, don't expect it to be quiet enough for a preamp to operate successfully without getting swamped.

Couldn't of said it better Bill....thanks for filling in on the OP's query back to me.

[kt2728]

I will have to make an appointment at the local MSS and make sure it has not drifted.

[Bill_G]

Couldn't of said it better Bill....thanks for filling in on the OP's query back to me.

Ask me how I know. (big grin)

We run into this around here so often, it is embarrassing for the trade. So, I ask our guys "how well will a hearing aid work when the band is playing?", or "how fast will your Corvette go in five o'clock traffic?". Tower space is always scarce. Quiet tower space is even scarcer. Broadcasters love the revenue tenants generate, but many people don't think about site noise until after they have installed their system, and their inbound range is not what they expected. Sometimes, even when they choose a site that is one mountaintop over and two miles away, their antenna is at elevation with a broadcaster right in the main beam path turning their receiver into a stone. Other times, the land mobile site owner wants the revenue a low power TV brings in, and they allow the new tenant to install at the top where everyone else's receive antennas are. Or just ten feet down. It can be a challenge sometimes to keep two-way systems working well, or make a new system function at all.