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Has anyone tried this FM diversity antenna circuit design from the "Electronics Now" magazine?

Discussion in 'Radio and Communications' started by thebestofall007, May 7, 2016.

  1. audioguru

    audioguru Well-Known Member Most Helpful Member

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    There is a fairly new Arab grocery store with a Greek name in my city and there is a fairly new Chinese grocery store. When they opened they were not very busy they played awful and odd Arab or Chinese music on the PA system which I think drove away people like me who are not Arab or Chinese. But recently I went to both stores and the PA system was playing Canadian Pop music and they were crowded with people like me.

    I think if Canadian FM radio stations played two songs then 5 minutes of commercials repeat ad infinitum then most listeners would go away and the radio stations would become bankrupt, or they would reduce the commercials time.
     
  2. audioguru

    audioguru Well-Known Member Most Helpful Member

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    I have always wanted to use an expander to cancel the effects of compression in most recorded music. But finding the threshold and amount of expansion would be difficult to get them correct. Did yours work fairly well? How did you set it up, with trial and error?
     
  3. KeepItSimpleStupid

    KeepItSimpleStupid Well-Known Member Most Helpful Member

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    There's some info here (sell sheet): http://vintagedbx.free.fr/dbx.html

    The 5bx is supposedly superior with a better ability to compress.

    The unit runs about $400 USD on ebay with a remote. Retailed for $1000.00 USD in it's day. It worked really well. It splits the audio into 3 bands and 1 for impact and works on each separately.

    I stuck mine in the tape monitor loop. You basically have a transition level adjust where you set the bar graph display in the center. There are two potentiometers in the rear labeled impact release rate and HF (High Frequency) transition level. It does what I would call derivative processing or the ability to increase the rise time too. So, you can accent the attack on say piano strings.

    I hooked it up once to an amp I fixed and it could not handle the high speed transients when impact restoration was turned up.

    The 4bx has a few quirks: The device when the plug is pulled loses all of it's settings and the audio goes to maximum.

    It's not CFL friendly. A CFL lamp can stop the front panel and the remote from responding. Fixable with a replacement receiver board. With the replacement receiver, it's possible to send low level TTL pulses that mimics the IR codes.
     
  4. dave

    Dave New Member

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  5. KeepItSimpleStupid

    KeepItSimpleStupid Well-Known Member Most Helpful Member

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  6. bountyhunter

    bountyhunter Well-Known Member

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    Funny. My brother in law was a big classical music fan and the FM stations he listened to used dynamic range expanders. They adjusted them until they started getting complaints that people couldn't hear the quiet parts....
     
  7. thebestofall007

    thebestofall007 New Member

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    The responses to my thread have been interesting, guys. Thank you. I enjoy reading these discussions and learning new things. This thread isn't dead yet, though, as I'm still waiting for others to chime in.
     
    Last edited: May 16, 2016
  8. Mikebits

    Mikebits Well-Known Member

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    I think this has been the case in the US. Most listeners grew tired of the deluge of commercials and have long since abandoned FM radio for Satellite radio (which is a pay/month service). This in turn has sent all the good talent for talk/comedy radio to sign deals with Satellite radio. The end result has been more commercials on FM with lesser quality content. Most of the stations around here (San Diego Ca), are now originating from Tijuana.
     
  9. MikeMl

    MikeMl Well-Known Member Most Helpful Member

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    You guys are obviously not NPR listeners. I listen to KNAU or other NPR affiliates.
     
  10. dr pepper

    dr pepper Well-Known Member

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    I thought this would be ok for vhf use, however after looking at the blurb I found that the system uses the 19kc pilot tone on fm stereo stations.
    An interesting article non the less.
    Actually I rarely listen to Fm, but I do listen to broadcast am and lw, and sometimes shortwave if cricket is on.
     

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