Dodgy Modulation from SUR

News Comments Off
Jul 162011

The Society have received another flurry of complaints about Radio SUR. Society memebrs endeavoured to locate their transmission location without success. The signal was so over modulated that much of the power was in the sidebands making signal strength direction finding impossible. A quick look at the modulation using the PIR 75 Modulation meter showed a horribly over modulated signal.

A look at the modulation power we see

Clearly limiting is not a part of their transmission chain

Compare these graphs with those of The Flea on LPFM Observer here. This is a good example of an LPFM station that is not a good neighbour. This station has continually trampled on other stations with blatant disregard for other broadcasters. Now their excsive modulation is now impacting on stations on adjacent channels.

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Posted by webmaster on July 16, 2011 at 10:39 am Tagged with: , , , , , , ,

Rogue "out of band" urban station in Mangere

News Comments Off
Jul 162011

There have been reports of a rogue LPFM station broadcasting on 106.5 MHz in Mangere Central. The station is identifying itself as 106.5 FM so it is not accidental.

If anyone knows who is responsible for this station please contact the society at webmaster@lpfmnz.com

 

 

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Posted by webmaster on July 16, 2011 at 9:22 am Tagged with: , ,

Become a Society Insider

News, Uncategorized Comments Off
Jun 152011

Want to be kept up to date with news and events?  Join the LPFM Society Insiders mailing list. You will be notified of upcoming meetings, news and events. Simply click here and sign up. You can choose to receive each email individually or a daily digest. Do it now and become a Society Insider.

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Posted by CharlesGraves on June 15, 2011 at 8:35 am

The Complaint That Wasn't

News Comments Off
Jun 092011

The Society recently received a complaint from a new member that another LPFM Station was swamping his signal. A visit by a Society member revealed a different story. The Society member reported back:

  • The problem is in your antenna/coax
  • Impedance was 24 ohms. should be 50
  • SWR 2.1:1. should be 1.5: max. (But  better if closer to 1.1:1)
  • Z=10. Z should be as close to 0 as possible but certainly below 3 or  4
  • The coax RG58 is 6 years + old and looks a bit suspect.
  • the connections to the JPole appear to be perished and probably letting water into the cable..
  • I would remake the RF choke with 4 turns at 100 mm dia rather than the 2 turns as at present.

It has been reported that the station is now back on air. Another great result from the Society.

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Posted by webmaster on June 9, 2011 at 8:03 am

Illegal West Auckland Station Located

News Comments Off
Jun 082011

Great work by Society members to locate and educate the illegal station in West Auckland. A frequency change and  power adjustment sees them broadcating within the GURL

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Posted by CharlesGraves on June 8, 2011 at 7:56 am

New station broadcasting illegally in West Auckland

News 2 Responses »
Jun 062011

There is a new LPFM station broadcasting illegally in West Auckland on 87.5MHZ. The station identifying themselves as Amped or Amp’d FM or broadcasting outside the terms of the GURL. 87.5 is not an available frequency. Society members have idrntified the signal to be coming from around Glengarry Rd.

If you have any information on how to conatact this station please email the webmaster.

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Posted by CharlesGraves on June 6, 2011 at 4:49 am Tagged with: , , ,

Samson Audio Meteor Mic

News Comments Off
Apr 032011

Future of Audio Recording?Looking for a new way to record content for your radio station?. Well look no further. Samson Audio have released the Meteor Mic based loosly on the look and feel of the Shure 55SH. Connect the Meteor Mic  to your iDevice running MultiTrackDAW from Harmonicdog and you have a full digital multitrack with portable microphone.

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Posted by webmaster on April 3, 2011 at 5:55 am Tagged with: , ,

Pira 75 Analyzer

Member Services, News Comments Off
Nov 282010

One of the most challenging elements of FM broadcasting is accurately setting up modulation levels. Schedule 1 h of the GURL specifies

(h) Unwanted emissions shall not exceed the limits as follows;

Unwanted Emission            Frequency Range                    Spectrum Analyser
Limits – in the                         from carrier                              Resolution  Bandwidth
resolution bandwidth

-25 dBW                                   128 to 240 kHz                          Not to exceed 10 kHz*
-35 dBW                                   240 to 600 kHz                         Not to exceed 100 kHz*
-56 dBW                                   > 600 kHz                                    100 kHz

* The spectrum analyser shall be set for 5 minute maximum hold.

But what does all this mean? I can guarantee most LPFM broadcasters just plug everything in and adjust the volume to sound similar to another station. The danger of this approach is that many stations use specialised and expensive processing. High volumes are obtained by reducing the dynamic range. Trying to match the volume of a commercial radio station will inevitably lead you to breaching the GURL. With a PIRA75 modualtion monitor you can set your modualtion levels correctly. It will also assist with the ability to deal with interference complaints. This will be available to members.

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Posted by webmaster on November 28, 2010 at 2:58 am Tagged with: , , , , , ,

Running an illegal antenna?

News 3 Responses »
Nov 232010

Under the GURL antenna must be omnidirectional and vertical, unlike this one!

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Posted by webmaster on November 23, 2010 at 5:05 am Tagged with: , , , ,

Lodge an interference complaint.

Member Services, News 1 Response »
Nov 232010

Another free service to Society Members. Lodge a complaint about an interference issue and we will do our best to analyze the complaint and make recommendations. Be warned though, as part of the process we will also be looking at your station. The complaint form can be found here.

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Posted by webmaster on November 23, 2010 at 5:04 am Tagged with: , , , , ,
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