Lectro blocks 21 & 22 in the U.S / Canada

[cjh]

Hi all, I am heading to the U.S for a doco shoot and am planning on taking my block 21 wireless mics and block 22 camera hop (SR5 Rx + 2 LMa Tx). I will have scanning ability on both blocks.

At this stage we will be shooting in LA, San Antonio, Toronto, and Chicago. I understand that 21 is ok but 22 not as good in places like LA. As my block 22 is primarily my camera hop and both TX and RX will have good line of sight and not be far apart much of the time that this should still be ok...

Any thoughts or feedback appreciated (I will be running a back up recording of all audio if the link does throws a wobbly to be safe).

Thanks,

Chris.

[studiomprd]

this has been "discussed to death" many times over the years, and the basics remain the same:

you can get a couple of channels working on any, and every block just about anywhere in the world.

Interference varies from location to location, and even moving less than a km can make a huge difference in what interference there is,  Television broadcasters can be checked on all the wireless manufacturers' sites, and others (Wolfie just posted a number of excellent links in another thread!  Television broadcasters are only a small part of the total interference picture at any given location.

I am in Los angeles, and doing a stage show with a 4 full Venue's (VRS's), and am currently using 3-4 frequencies on each and every block from 20-28!!  I get uniformly excellent range, and all the TX's are LM's at 50 mw!!

[cmassey]

You should be fine in San Antonio!!!  I use 21-22-27 there often with no problems.

[hemmerlinj]

I've definitely had problems with Block 22 in Chicago.  Particularly close to the lake.  Further inside of the city not much problems.  Block 21 has generally seemed to work fine anywhere I've used them.

J Hemmerlin

[Marc Wielage]

You can try the Lectro frequency chart at this link. This will at least warn you where existing digital TV frequencies are being used in given cities.

Block 22 is getting crowded in LA, that's for sure. 21 is better. I used eight channels spread out on Block 19 last weekend on a project, and it went flawlessly. Only a couple of minor spikes on a scan, so I had lots of room available. I bet your blk 22 camera hop will work provided you do a walk test and scan prior to the shoot. A lot depends on the specific part of LA, particularly downtown or close to airports.

--Marc W.

[cjh]

Thank you all for your replies, very helpful and much appreciated.

Regards,

Chris Hiles.

[John Blankenship]

You can try the Lectro frequency chart at this link. This will at least warn you where existing digital TV frequencies are being used in given cities.

Currently, the Lectro "Station Lookup chart" is not a reliable source.  Unfortunately, it appears not to have been updated since prior to the digital transition.  Most of the analog allocations are no longer being used and some stations have shifted their digital frequencies following the transition.

John B.

[Marc Wielage]

Yeah, I think the best one is the one at the FCC's own website:

http://www.fcc.gov/fcc-bin/audio/tvq.html

That you can at least do a search on, and see which active HDTV channels occupy which frequencies in the VHF and UHF spectrum.

Shure also has some good info here:

http://www.shure.com/proaudio/products/us_pro_ea_dtv

I dunno why Lectro's information isn't kept more up to date.

Update: just found another more current source at this link:

http://www.fccinfo.com/

--Marc W.

[John Blankenship]

Marc,

Thanks for the links.

John B.

[John Blankenship]

Also, this:

http://www.sennheiserusa.com/findfrequency/

John B.

[studiomprd]

the Lectro page has been updated!

[Ric]

I’m thinking of buying a used lectrosonics 411 transmitter, and receiver. It’s Block 21. They’re in great condition and the price is right but I’m a bit leery, because I live in work in New York City. Opinions please. Thank you in advance.

[LoganSound]

I’ll put in another resource, oft-used in live event industry but free: Shure Workbench which allows for location based TV frequency lookup, importing of CSV frequency scans from RF Explorer, and coordination and tracking of frequencies across different parts of production.

[OB1]

4 minutes ago, LoganSound said:

I’ll put in another resource, oft-used in live event industry but free: Shure Workbench which allows for location based TV frequency lookup, importing of CSV frequency scans from RF Explorer, and coordination and tracking of frequencies across different parts of production.

 

Great resource:

https://www.shure.com/en-US/support/tools/frequency-finder