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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => Wireless and Communications => Topic started by: Al Rettich on May 31, 2017, 08:15:05 am

Title: Telex BTR-800 C3
Post by: Al Rettich on May 31, 2017, 08:15:05 am
Hey folks, I was just wondering if anyone had the channel / frequency for the Telex BTR-800 C3 band range. I'd like to add it to my RF calculation software, but have looked for the past two evenings to get all the information I need to add to software, but cannot find channel specific frequency. Hoping someone might have it?
Title: Re: Telex BTR-800 C3
Post by: Scott Helmke on May 31, 2017, 09:51:36 am
Wireless Workbench has all of that data easily available - Tools -> Equipment Profiles, then select the Tuning tab.
Title: Re: Telex BTR-800 C3
Post by: John Sulek on May 31, 2017, 10:38:34 am
Hey folks, I was just wondering if anyone had the channel / frequency for the Telex BTR-800 C3 band range. I'd like to add it to my RF calculation software, but have looked for the past two evenings to get all the information I need to add to software, but cannot find channel specific frequency. Hoping someone might have it?

This is from 2010 off of the Bosch site
Title: Re: Telex BTR-800 C3
Post by: Brad Harris on June 01, 2017, 04:57:27 pm
"Channel Map" is the secret for Google (and other searches) with the product name for future reference (i.e. "BTR800 Channel Map" "BTR80n Channel Map", etc).

Very handy as I'd rather program BTR in default G/C rather than reprogramming all the units (when possible)

BRad
Title: Re: Telex BTR-800 C3
Post by: Ike Zimbel on June 01, 2017, 10:24:03 pm
"Channel Map" is the secret for Google (and other searches) with the product name for future reference (i.e. "BTR800 Channel Map" "BTR80n Channel Map", etc).

Very handy as I'd rather program BTR in default G/C rather than reprogramming all the units (when possible)

BRad
Man, I hate to be the bearer of bad news but you guys DO realize that every BTR band split except E-88 is going to be a no-fly zone as soon as the post 600MHz auction re-pack takes place, right? And that E-88 is a no-fly in many major cities in the US because the belt-packs are in Ch-14,15,16, which are reserved for public safety? Sorry for the buzz kill... :'(
Title: Re: Telex BTR-800 C3
Post by: Paul McDermott on June 02, 2017, 04:24:32 pm
Man, I hate to be the bearer of bad news but you guys DO realize that every BTR band split except E-88 is going to be a no-fly zone as soon as the post 600MHz auction re-pack takes place, right? And that E-88 is a no-fly in many major cities in the US because the belt-packs are in Ch-14,15,16, which are reserved for public safety? Sorry for the buzz kill... :'(

The "3" band has 11 Mhz of bandwidth in the Gard Band Between Uplink and Downlink of the auctioned 600 Mhz.
Title: Re: Telex BTR-800 C3
Post by: Cameron Stuckey on June 02, 2017, 05:50:55 pm
The "3" band has 11 Mhz of bandwidth in the Gard Band Between Uplink and Downlink of the auctioned 600 Mhz.

Actually only 10MHz in the Duplex Gap(2MHz in the Guard band), and then 6MHz unlicensed(4MHz exclusively Part 74), and then only 20mW power limit in the Guard Bands and Duplex Gap. 2MHz of spectrum for the "1", and 6/10MHz of spectrum for the "3".

And the 20mW limit poses an interesting dilemma with the TR-825 and TR-800. Both the packs transmit up to 50mW with an auto-power reduction based upon RSSI of the basestation. So frequencies may be legal, but transmission power would not always be legal.
Title: Re: Telex BTR-800 C3
Post by: Ray Aberle on June 03, 2017, 03:18:24 pm
Man, I hate to be the bearer of bad news but you guys DO realize that every BTR band split except E-88 is going to be a no-fly zone as soon as the post 600MHz auction re-pack takes place, right? And that E-88 is a no-fly in many major cities in the US because the belt-packs are in Ch-14,15,16, which are reserved for public safety? Sorry for the buzz kill... :'(

Yeah, I was wondering about, after I was looking at their frequency charts. Do we have any insider information as to whether or not they'll be able to re-program, or otherwise help transition their users to new legal bandwidth?

-Ray
Title: Re: Telex BTR-800 C3
Post by: Mac Kerr on June 03, 2017, 05:58:32 pm
Yeah, I was wondering about, after I was looking at their frequency charts. Do we have any insider information as to whether or not they'll be able to re-program, or otherwise help transition their users to new legal bandwidth?

Pretty unlikely. BTRs are old technology and Telex is working on a new system, as is everyone else. Newer systems have more features/better performance. I think parts may no longer be available for BTRs.

Mac
Title: Re: Telex BTR-800 C3
Post by: Scott Helmke on June 03, 2017, 09:09:57 pm
I've been told that Telex can still re-band those systems to be legal, but why bother?  Intercom doesn't need high fidelity or low latency, so newer systems are moving off into VHF (RAD), 1.9GHz (FreeSpeak), etc. to leave more UHF space for "legacy" UHF-R and PSM.

EDIT: Back during the 700MHz closure we had our C6 system rebanded for C4.  I think it cost about $1000 less than a complete new 4-drop system.  So something like 80-90% of the cost of a complete new system.

EDIT of the EDIT: In 2011 we paid $1500 for the base station to be rebanded and $350 for each beltpack.

Seriously, I'm not going to miss BTR all that much. Annoying to tune, gulps down the batteries, noisy fan in the base station, etc.
Title: Re: Telex BTR-800 C3
Post by: Ike Zimbel on June 05, 2017, 12:28:35 pm
I've been told that Telex can still re-band those systems to be legal, but why bother?  Intercom doesn't need high fidelity or low latency, so newer systems are moving off into VHF (RAD), 1.9GHz (FreeSpeak), etc. to leave more UHF space for "legacy" UHF-R and PSM.

Agree with most of this BUT, latency in intercom, as well as how the side tone is derived can be of critical importance. If someone is giving a "Go" cue, or even more importantly a "STOP!" cue, latency can be a problem. An important thing to be aware of is that analog systems like BTR and Rad Com generate side-tone by making the full round trip from pack-to-base-station-to-pack virtually instantaneously, while IP based systems like Free Speak generate side-tone locally in the pack (because the latency would create an echo to the user). There are two critical issues with latter system: 1) when the person on the pack hears themselves say "Go" or "Stop" isn't, by some tens of milliseconds, when the rest of the PL hears it, and 2) there's no guarantee that the rest of the PL heard it anyway.
This is why choosing the type of wireless com to use can be very important when life safety is involved, say, for rigging and automation folks when a show involves flying people in-and-out or moving set pieces etc.
Full disclosure: I am the manufacturer's rep for Radio Active Designs in Canada.