Re: LF: WRC-2012 proposal for 'near' 500kHz band(s)

["wd2xgj@gmail.com"<wd2xgj@gmail.com>]

David,
A good receiver will have something upwards of  60dB  i.f. rejection, consumer models somewhat less.
The bottom line is that nobody cares about MW (except hams!)
The martime group is lobbying governments to create new digital data services at 500, it remains to be seen if they will get their wish. In the meantime the maritime interests will fight like mad to hold on to the frequencies whether they use them or not!
73 Warren K2ORS


Sent via DROID on Verizon Wireless

-----Original message-----

From: David Pratt <david@g4dmp.fsnet.co.uk>
To: rsgb_lf_group@blacksheep.org
Sent: Wed, Mar 2, 2011 11:20:07 GMT+00:00
Subject: LF: WRC-2012 proposal for 'near' 500kHz band(s)

I was somewhat disturbed by the piece in last Sunday's GB2RS news that
gave preliminary information about the proposals to WRC-2012 for an
allocation near to 500kHz.

It states that the initial proposal for 15kHz allocated was between 415
to 526.5kHz. Due to future maritime use, the RSGB is proposing
472-487kHz, while the US will be proposing two bands totally 15kHz, viz
461-469 and 471-478kHz.

I wonder whether any thought has been given to the fact that the IF of
medium wave broadcast receivers in the UK is usually either 465kHz or
470kHz? In the US the IF is more usually 450kHz or 455kHz.

This being so, any operating particularly at the lower end of 472-487kHz
is very likely to cause interference to AM broadcast reception.

I recall when I took my Morse test at Portpatrick in 1954. Broadcast
reception was repeatedly interrupted by GPK operating on 472kHz.

Sorry it this has been covered before. I could have missed it.

73 de David G4DMP
--
+ - - - - - - - - - - - - - - - - +
| David M Pratt, Kippax, Leeds. |
| Website: http://www.g4dmp.co.uk |
+ - - - - - - - - - - - - - - - - +