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Re: LF: RE: Japan on 475 kHz.

To: [email protected]
Subject: Re: LF: RE: Japan on 475 kHz.
From: pa3abk <[email protected]>
Date: Sun, 21 Dec 2014 15:41:56 +0100
In-reply-to: <[email protected]>
References: <[email protected]om> <[email protected]>
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Dear Hideho,

Assume in JP  MF BCST stations are also likely to disappear.
In NL it's expected that all MF station will be QRT within a year or 2.
But NL is rather small and the internetconnections are very dense and most of them high speed (> 100Mb).
A lot of alternatives available.

I assume that the 200m rule is not particular for BCST MF stations, but the fact that ADSL connection can suffer from slow modems.
Especially in countries were the telephone lines are above ground.
JP is more widely and expect that rural connections are far most above ground.
I remember a discussion in BlackSheep about this issue with Britisch
Telecom. If I recall correctly the line check of ADSL is done in the
same band we are using for MF. If the check interferes with the "our
signals" the server will automaticly lower the internetspeed and finally
to an unacceptable value. The user is mostly not aware and the provider
software doesn't reveal why the connection is bad. At the end the
provider will send a new modem. The user is happy with the high speed,
until his neighbour starts WSPR again in the weekend.
The emails are lost here but there was a PDF mentioned with an improved
ADSL filter which could subside this issue.
Jan/pa3abk

Hideho YAMAMURA schreef op 21-12-2014 om 13:20:
Dimitris and all LF/MF,

Yes, in JA, 630m will be permitted at EIRP 1Wmax., effective Jan.05, 2015.
Official Directive was published on Dec.17, 2014.

however,
there are following conditions (I think, first announced on Oct.10):
(1) there are no house or office within 200m radius,
     other than owned by the station owner.
(2) OR, agreements are obtained from the houses or offices within the 200m.
(3) on site test will be conducted before permission. ("for some time" they 
say).

It seems that the officials have concerns on QRM to MF broadcast signals,
like 936kHz, 945 kHz, 954 kHz... the 2nd harmonic
and/or 1413 kHz, 1422 kHz, 1440 kHz... the 3rd harmonics.

Several stations are preparing LPF,
and are finding/found places for the on site test, as portable stations.
There is hot discussion on these on the internet in JA.

I would like to know the situations in the already operating stations.
Do you have any BC QRM problem ? (I mean making interference, not receiving),
and what care do you take ?
LPF, what kind, other means ?
How much is your harmonic attenuation ? or filter attenuation ?
Information highly appreciated,

BTW, I myself, is not prepared for 630m, yet.

  Hideho YAMAMURA, JF1DMQ


-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Dimitrios
Tsifakis
Sent: Sunday, December 21, 2014 8:26 AM
To: [email protected]
Subject: LF: Japan on 475 kHz.

Hello group,

I have received an email from a friend in Japan informing me that Japanese
amateurs gain access to 630 m from 05/Jan/2015. There are some restrictions
on power and vicinity to other houses. Does anyone have more information
on this?

73, Dimitris VK1SV


--
pa3abk <-> dordrecht jo21it
Sent by Philips STB-75 with T100

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