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[Nathan Riddle]

I'm quoting for a church install with 4-6 wireless mics. I'm working with another company (who was once a mentor, now we are more like peers). He got the call, but he's trying to retire so we're working together

I said we should quote distribution & antenna. He disagrees as it costs more.

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67' x 50' (L x W) Balcony is 13ft in the air. Antenna units will be on balcony. So max distance would be 67ft.

Systems in consideration. Standard 1/4 wave with receivers. VS Distro + LPDA antennas.

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What is my duty to the client RF performance wise vs cost wise? I don't care about who's right, I just want what is 'best' (I know  a loose term) for the client.

My argument is with the 600MHz sell off, the 470-608MHz range is being pretty squished and going to be full of interference in the next 5-10years. It's also on a military base... so plenty of nearby interference could be generated.

[John Daniluk (JD)]

depends where you put the receivers.    close to source with remote monitoring,  directional antennas,  digital or analog transmitters,  what rf sources are near by.   pricing WILL be an issue.  If possible do a long rf scan (several days) to see what is currently there, then make a decision. 

jd

[Nathan Riddle]

depends where you put the receivers.    close to source with remote monitoring,  directional antennas,  digital or analog transmitters,  what rf sources are near by.   pricing WILL be an issue.  If possible do a long rf scan (several days) to see what is currently there, then make a decision. 

Apologies, I meant to include some of that info in the original post. I updated that now.

Receivers at the booth in the balcony so 10ft in the air behind a wooden/sheetrock wall. After that direct line of sight to the stage. (so over the congregation).

Cheaper units, think SLX/ULX or XSW2/EW100 300-600ea.

I don't think the long rf scan is possible as this is more of a send us a quote and we'll get 3 others and then go with whoever we want (is cheapest).

[Jerome Malsack]

Frequency Coordination is not going to help or prevent any problems if they have a conflict without the frequency scans.  You can tell them this and they may not agree.  I have a school doing the same thing for a theater and they do not want the frequency scan and want 8 or more working.  There is already with 4 UHF interference and they can not scan and find a 5th.  So I have to bring in my old VHF systems to get them back up to 8.  I use the antenna active distrobutions D12 from Audio Technica.  This helps my VHF to allow for 12 working vhf channels.  With out the frequency scan they are guessing.  So no Guarantees or warrantees.

[Jerome Malsack]

The other thing is receivers also need the 1/4 wave separation on antennae.  The school and students tend to stack them one on the other.  You can rack mount them yes but you should use the Antenna Distro to provide the signal to prevent the receiver antenna from interacting with each other. 

[Henry Cohen]

What is my duty to the client RF performance wise vs cost wise? I don't care about who's right, I just want what is 'best' (I know  a loose term) for the client.

Your ethical obligation is to inform your client (the "other company" or the church, whoever it may be), of the optimum method for achieving the desired performance, then paring down from there based on established budget and/or existing equipment. It may very well be that the budget will not allow for an optimum equipment deployment; in which case you should inform your client of the potential performance shortfalls. 

My argument is with the 600MHz sell off, the 470-608MHz range is being pretty squished and going to be full of interference in the next 5-10years. It's also on a military base... so plenty of nearby interference could be generated.

Both these may or may not be factors: 1) Have you checked the repack plan for this market, and 2) have you done any scans over time, or at least on Sunday mornings, for potential RFI from base operations?

[Henry Cohen]

Apologies, I meant to include some of that info in the original post. I updated that now.

Receivers at the booth in the balcony so 10ft in the air behind a wooden/sheetrock wall. After that direct line of sight to the stage. (so over the congregation).

Cheaper units, think SLX/ULX or XSW2/EW100 300-600ea.

I don't think the long rf scan is possible as this is more of a send us a quote and we'll get 3 others and then go with whoever we want (is cheapest).

So if they simply want equipment pricing and will be getting multiple quotes, it should be up to the church to list the equipment they want and pass that around to the resellers. This way everyone is quoting the same thing. If the church doesn't know what they need, then it becomes a question of do you want to provide a system design, or two, or three, at no charge?

I realize not everyone is in a position to turn down a sale, but if I read your post correctly, the church simply wants cheap without much thought or desire given to really understanding the equipment and performance issues at hand, this is the type of inquiry I tend to steer towards Sweetwater / Full Compass / B&H Photo. In the end, the profit isn't worth the headache of a dissatisfied customer who was only concerned about price.

And yes; a pair of LPDA's appropriately deployed with low loss coax feeding a proper multi-coupler (antenna distributor) is the correct way to do this. This installation may also need some additional filtering if you really feel spectrum will be very congested and with a high noise floor.

[Nathan Riddle]

You can rack mount them yes but you should use the Antenna Distro to provide the signal to prevent the receiver antenna from interacting with each other.

That's my thoughts exactly. They will get placed in a rack. I don't like the idea of 6x 1/4 wave antenna in a rack all interfering with each other.

Your ethical obligation is to inform your client (the "other company" or the church, whoever it may be), of the optimum method for achieving the desired performance, then paring down from there based on established budget and/or existing equipment. It may very well be that the budget will not allow for an optimum equipment deployment; in which case you should inform your client of the potential performance shortfalls. 

Thanks, that's a simple enough attitude that I can work into a proposal to help 'brief' the client (base chapel).

Both these may or may not be factors: 1) Have you checked the repack plan for this market, and 2) have you done any scans over time, or at least on Sunday mornings, for potential RFI from base operations?

No repack towers are planned within 50+ miles.
https://www.google.com/maps/d/u/0/viewer?hl=en&hl=en&mid=1b_LOMSl3Xewr7VEzK6OkqrlJKJQBwqgU&ll=30.693228819928517%2C-86.88904858800845&z=8

Is there a resource that shows the TV stations that are moving into the 500MHz spectrum from the 600MHz spectrum?

I've done some scans (shorter ~10-15m) with my RF Viewer in various places indoors (mostly venues I'm at for gigs). I should probably do some outdoors.

I didn't think about just showing up and doing scans on a Sunday morning. I could do that.

So if they simply want equipment pricing and will be getting multiple quotes, it should be up to the church to list the equipment they want and pass that around to the resellers. This way everyone is quoting the same thing. If the church doesn't know what they need, then it becomes a question of do you want to provide a system design, or two, or three, at no charge?

I realize not everyone is in a position to turn down a sale, but if I read your post correctly, the church simply wants cheap without much thought or desire given to really understanding the equipment and performance issues at hand, this is the type of inquiry I tend to steer towards Sweetwater / Full Compass / B&H Photo. In the end, the profit isn't worth the headache of a dissatisfied customer who was only concerned about price.

And yes; a pair of LPDA's appropriately deployed with low loss coax feeding a proper multi-coupler (antenna distributor) is the correct way to do this. This installation may also need some additional filtering if you really feel spectrum will be very congested and with a high noise floor.

Military Base Chapel, so they have to get multiple quotes with a basic RFP (I doubt the other companies will even do a site visit, but maybe *shurg*). Chapel doesn't know exactly what they need or want, but there is a fairly knowledgeable tech guy that we're working with in addition to the sergeant in charge of the quotes/bids.

I could turn it down, but my thinking they are price driven is mostly based upon my experience with military bids as a contractor. This instance could be different. That said, I think my/our bid will be what I need/want and still under the other companies bid.

And I agree, I'll walk away if it becomes a customer who was only concerned about price.

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Thanks all

[Jean-Pierre Coetzee]

Do more than one quote and clearly explain the reasoning.

I would do one with LPDAs, one with Dipoles and then one without with a big disclaimer that they need to sign that you cannot be held responsible for anything if they go with the one without.

Also look around at pricing on a few different manufacturers distros, you do not need to use the same brand, it just needs to be in the same frequency range.

Considering that this is going into a rack IMHO a distro is non-negotiable regardless of what antenna gets placed onto it(1/4 wave will not work)

Do you need to price in the rack as well?

[Stephen Swaffer]

To me this is a tough one-I won't argue that a distro is the right way.  That said, I run 5 SLX systems in a nearly identical situation-in a balcony roughly 10 ' in the air 50-75' from mics no distro and breaking all kinds of rules.  Only time I have ever had a drop out, I discovered an antenna disconnected.  (A distro is on my wish list!)  The one thing in my favor is a rural location-in a small town so RF is relatively quiet.

As an electrical contractor, I was often asked to design/bid a job "to code".  Really?  I can usually do a job to code you won't be happy with-but that is OT.  Now in a role where I am often seeking bids I do my best to let everyone bid apples to apples.  Sometimes I pay a potential bidder to do the design (think general contractor-lets reconfigure a restroom)-so I have something to have bidders bid for, but the designer doesn't have to eat that time.  Maybe they would be open to adding some detail to the RFP so that they can get a real price on what they need?  That's better for them and you than you coming back in a few months to fix the cheap bid.

[Nathan Riddle]

Well, we met again with the technical director (lack of a better title, but seems appropriate).

Again distro vs no distro came up. I couldn't really get a word in. Mostly just "it adds cost, and cost = bad; so don't do it..." Seems like the client was thinking of a 'shelf' on the front of the balcony so that's better than racked. I'd rather see nicely racked units with paddles, but that's me. $1k or 3% for distro's and antenna isn't that much...

As far as quote or RFP, I really don't know what they want government procurement procedures... I'll figure that out and do what they need.

Thanks for the ideas everyone!

[ProSoundWeb Community]