The above Ad will no longer appear after you Sign Up for Free!

Sennheiser ew

Discussion in 'Sound, Music, and Intercom' started by peacefulone61, Jan 11, 2017.

  1. peacefulone61

    peacefulone61 Active Member

    Messages:
    151
    Likes Received:
    5
    Occupation:
    Technical Director
    Location:
    Somerset Ma
    I have five body packs and transmitters that are in the c band 718-790 frequency I am trying to replace the antenas due to being worn out from usage. I am having difficulty locating the antennas and was wondering if there was a way I could convert the receivers and the transmitters to a different frequency. Since I can buy a and b band antenas would it be as simple as just switching these out?
     
  2. rhedgehog

    rhedgehog Member

    Messages:
    35
    Likes Received:
    3
    Location:
    Tacoma, WA
    No. The frequency range is determined by the internal hardware, not just the antennas. That being said, the Sennheiser C band is now illegal for use in the US, as the FCC changed regulations some years back to prohibit wireless microphones from operating in the 700mhz band. Your two best bets would be to either sell your old wireless to someone overseas where that band is still legal, or to make use of Sennheiser's trade-in program, where if you buy replacement wireless, you can send in your old ones for a partial refund.
     
  3. JD

    JD Well-Known Member

    Messages:
    3,506
    Likes Received:
    701
    Location:
    North Wales PA
    Sadly, the C band is kaput in the US. If you need replacement antennas before you sell them overseas, there is very little difference between the A, B, and C ban antenna. They are slightly different lengths, optimized for the band they work in, but I have tried swapping them around for the fun of it, and it really doesn't change any of the RF level readings I get. You didn't say if it was G1, G2, or G3 (generation) so the link is for the G1 which screws on. The G2 and G3 are available (same site) but required a bit more disassembly.
    Here is the B band one: http://www.fullcompass.com/prod/050731-Sennheiser-A18-2
     
  4. peacefulone61

    peacefulone61 Active Member

    Messages:
    151
    Likes Received:
    5
    Occupation:
    Technical Director
    Location:
    Somerset Ma
    The school will not let me sell them or trade them in they insist they have permission to use them and will not even let me rent additional equipment. So if I need Mocs I have to use those. I have shown them the the frequency ban and everything the FCC has put out about it. They insist they have permission
     
  5. rhedgehog

    rhedgehog Member

    Messages:
    35
    Likes Received:
    3
    Location:
    Tacoma, WA
    Considering the 700mhz band is now reserved for Public Safety, among other things, get in writing from your superiors their willingness to interfere with police, fire, or medical communications. Alternately, demand to see written permission from the FCC allowing the continued use of these mics. You can also mention that FCC fines can easily range in the tens of thousands, should the school be caught. If all else fails, you could always anonymously report them to the FCC and they will learn the hard way. Whatever you do, CYA they whole way with email chains documenting your concerns and attempts to become compliant.
     
  6. venuetech

    venuetech Well-Known Member

    Messages:
    1,215
    Likes Received:
    163
    Occupation:
    aud man
    Location:
    AK,
    The school would have on file the appropriate documents from the FCC. (Haha) Ask them for a copy. (Ya Shure yabetcha) After that give the transmitters to an administrator and ask for replacement parts, (new receivers, new transmitters)
    I upgraded the entire system by getting a bid on a new package with all the trimmings and plopping that with the FCC info in front of the operations head. It did not happen till the next fiscal year but it did happen.

    It is far easier for me to toss old equipment like that in the dumpster (after replacement) then it is to trade or sell. Just something that happens when you deal with a public entitie like a school district.
     
    Last edited: Jan 11, 2017
  7. JD

    JD Well-Known Member

    Messages:
    3,506
    Likes Received:
    701
    Location:
    North Wales PA
    Always surprises me when I hear about blockhead administrators! Their dime, they pay the fine. Not really worth the headache. As a student, there is only so much you can do before you start alienating people.
     
  8. JohnA

    JohnA Active Member

    Messages:
    106
    Likes Received:
    15
    Occupation:
    Lighting Designer/Technical Consultant
    Location:
    Philadelphia, PA
    This is directly from the FCC website, Bureau Office of Public Safety and Homeland Security https://www.fcc.gov/general/700-mhz-public-safety-spectrum-0

    The 700 MHz Band is an important swathe of spectrum available for both commercial wireless and public safety communications. The Band consists of 108 megahertz of spectrum running from 698-806 MHz and was freed up as a result of the Digital Television Transition.

    I would remove that equipment from service yesterday. Otherwise an anonymous tip to the FCC local field office is in order.
     
    Last edited: Jan 12, 2017
  9. FMEng

    FMEng Well-Known Member Fight Leukemia

    Messages:
    1,520
    Likes Received:
    279
    Location:
    Tacoma, WA
    In addition to the ample and correct evidence provided above, I will add:

    No permission exists unless they have a paper copy written on FCC letterhead. If the school had a license issued before June 12, 2010 it has been superseded by newer rules that became effective on that date.

    https://www.fcc.gov/consumers/guides/wireless-microphone-faqs
     
  10. venuetech

    venuetech Well-Known Member

    Messages:
    1,215
    Likes Received:
    163
    Occupation:
    aud man
    Location:
    AK,
    First get a quote for rental of the necessary equipment. Present a copy of the FCC rule to the administration, if they accept the FCC rule then present the rental quote. If they still insist on you using the transmitters and you are a student, have your parental unit call and question admins on why the school is telling students to violate federal regulations. And why they even have equipment on site that violates federal regulations.
     
    RonHebbard and JohnA like this.
  11. Moose Hatrack

    Moose Hatrack Member

    Messages:
    79
    Likes Received:
    22
    Location:
    Eudora, KS
    I bet the administration would tow a vehicle left in a fire lane on the campus. Same thing isn't it, interfering with the delivery of emergency services? What if it was YOUR heart atack?
     
  12. peacefulone61

    peacefulone61 Active Member

    Messages:
    151
    Likes Received:
    5
    Occupation:
    Technical Director
    Location:
    Somerset Ma
    I am not arguing that fact I am just trying to find a work around that was why I was wondering if I changed the antenas to a different frequency range on both end reciver and transmitter and if there were a few other small transistors would it work in a different range trying to make what I have work.

    They showed me a letter from the police department granting them permission to use wireless microphones in the 700 MHz range.
     
  13. JD

    JD Well-Known Member

    Messages:
    3,506
    Likes Received:
    701
    Location:
    North Wales PA
    Trust me, with 25 years electronics service experience (over 20k units serviced), if there was an easy way to convert them, I would! (Especially since the "B" band may now be on borrowed time.) I have part service lit on them and there are 24 parts that would need to be changed out, and then the front end would have to be tuned. Unfortunately, with everything tuned and changed, they still would not work because they also have different software burned into the EEprom that is built into the microprocessor! All the channel groups as well as valid tune frequencies are part of that software.
     
    themuzicman likes this.
  14. themuzicman

    themuzicman Active Member

    Messages:
    735
    Likes Received:
    71
    Occupation:
    Audio Engineer
    Location:
    On Tour

    No, it is not that simple. It won't be that simple - you'll simply need to go and buy or rent gear in an appropriate frequency range. You aren't going to get any answer you want to hear.

    As for your local police - I hate to break it to you, but federal law supersedes local law on this one, you're out of luck and your police need to brush up on their knowledge of those specific laws.
     
    Les likes this.
  15. peacefulone61

    peacefulone61 Active Member

    Messages:
    151
    Likes Received:
    5
    Occupation:
    Technical Director
    Location:
    Somerset Ma
    I understand all of this I was working in the industry when the switch first happened. I have never had such a reluctance to remove it. And if anyone calls the FCC I will lose my job over it.
     
  16. GreyWyvern

    GreyWyvern Apollo Staff

    Messages:
    548
    Likes Received:
    135
    Location:
    Fort Wayne, IN
    Well, now it seems you have two reasons to walk away; administration telling you to do something you know you shouldn't that has legal ramifications and now you are telling us they have apparently threatened to fire you if you keep pushing the subject. Doesn't sound like a good place to be employed. Might be better to run away.
     
    RonHebbard likes this.
  17. venuetech

    venuetech Well-Known Member

    Messages:
    1,215
    Likes Received:
    163
    Occupation:
    aud man
    Location:
    AK,
    I am not sure why a rental is an issue, for me it would come out of the show budget and for the most part be paid by box office income. With any surplus funds going into the drama club account.
    If it is a public school and you are a member of the educational support staff then you would likely have the backing of the union if threat of termination is an issue.
    I certainly cannot tell you to slap any old antenna on and muddle through this one production, that would be wrong.
    But even from where I sit ( just a few thousand miles away) I can hear a number of issues wrong with these transmitters, odd pops, bits of static, etc,etc..
    clearly these units are in need of factory service and arrangements should be made to get them "repaired". (nudge-nudge/wink,wink) Send them out to the factory for service as soon as you can.
     
    GreyWyvern likes this.
  18. Evans Poulos

    Evans Poulos Active Member

    Messages:
    106
    Likes Received:
    16
    Occupation:
    TD Skokie Park District
    Location:
    Chicago area
    While I agree with everything that has been said about the potential legal ramifications of continuing to use the equipment in question, I have to make a strenuous objection to those suggesting glibly that the OP simply walk away from a job that potentially supports the family, possibly provides medical coverage, and may not be so easy to replace. Let's try and keep in mind that some of these posts are not simply about a technical problem at root.
     
    peacefulone61 likes this.

Share This Page