Fw: [Premium-Rx] Hagenuk RX1001 and DRM reception

[Michael O'Beirne]

----- Original Message ----- 
From: "Michael O'Beirne" <michaelob666 at ntlworld.com>
To: "Premium-Rx" <premium-rx at mailman.qth.net>
Sent: Sunday, July 29, 2007 5:41 PM
Subject: Fw: [Premium-Rx] Hagenuk RX1001 and DRM reception


> Good evening fellow listeners,
>
> I am sure that Fabrizio gets excellent reception on the Milano Siziano DRM 
> station on 693kHz, but you won't receive that in the UK because our BBC 
> Radio 5 Live broadcast is also on that frequency at 150kW from Droitwich 
> (and also other sites, though with much less transmit power), and will 
> flatten pretty much everything else.
>
> The 6,095kHz DRM station is quite strong here and seems to be a lot wider 
> than 10kHz.  I personally regard DRM as a highly anti-social mode, and is 
> not clever when the signal level is low (which of course is when you most 
> need a robust system).
>
> The likely reason why Fabrizio has to offset his tuning is because the 
> Hagenuk may have separate sideband filters, each displaced into its 
> sideband.  The frequency of the panel LED display usually shows that of 
> the nominal carrier, and hence with a displaced USB filter, you have to 
> tune down to bring the signal within the passband.
>
> You get a related issue with NATO army HF frequencies.  The defined 
> frequency is not the nominal carrier but is roughly the centre of the 
> transmission.  To make life easier for everyone, the dial on the radio on 
> USB (the Army don't use LSB) is actually 2kHz higher than the nominal 
> carrier.  So if you wanted to listen to the BBC on 9410kHz (as one did to 
> catch the news when life was getting a bit boring), you set the backpack 
> on USB to 9412kHz.  The frequency offsets got complicated when operating 
> to other military units if they were using "civilian" gear, particularly 
> on FSK!
>
> 73s to all,
> Michael
> G8MOB
>
>
> ----- Original Message ----- 
> From: "Fabrizio Magrone" <fabrizio_magrone at tin.it>
> To: <premium-rx at mailman.qth.net>
> Sent: Sunday, July 29, 2007 3:25 PM
> Subject: [Premium-Rx] Hagenuk RX1001 and DRM reception
>
>
>>
>> Hello,
>>
>> I'm testing my new Hagenuk RX1001M receiver. It has a 10 kHz IF output to 
>> connect a recorder, but I was wondering whether it could be used for DRM 
>> reception.
>>
>> As you know, to listen to DRM broadcasts you need a 12 kHz output, 
>> usually downconverted from a 455 kHz IF, connected to your PC's 
>> soundcard; a software such as Dream then decodes the DRM signal.
>>
>> The Hagenuk's 10 kHz IF is not too far from the 12 kHz baseband requested 
>> by the DRM decoder, so I connected the output to my soundcard, launched 
>> Dream and... well, yes, it works.
>>
>> Thanks to the service manual kindly made available to the PremiumRX 
>> community, I had all the information I needed. The 10 kHz IF output is a 
>> 4-poles DIN socket; signal is available on pins 1 and 4 (the two lower 
>> pins in the socket).
>>
>> I used a shielded two conductors wire: the two wires connected to pins 1 
>> and 4, the shield to the receiver's case. You get a strong audio signals 
>> and the 10 kHz IF output must be set to a low level, at least in my 
>> setup.
>>
>> I set the receiver to USB mode, with the widest selectivity available (6 
>> kHz). I had to offset the frequency from 2.0 to 2.4 kHz lower than the 
>> transmitting frequency. For instance, Milano Siziano is transmitting on 
>> 693 kHz but I had to tune to 691.0 kHz; RTL is broadcasting on 6095 kHz 
>> but I had best decoding when tuning to 6092.6 kHz.
>>
>> DRM reception isn't excellent: signals must be strong for good copying 
>> and you need careful tuning, probably because the 6 kHz selectivity is 
>> too narrow; I don't think that the 10 kHz IF output, instead of 12 kHz, 
>> is a problem. But if you have got a R1001 and you want to try to listen 
>> to DRM broadcasts, you can have a try.
>>
>> 73
>>
>> Fabrizio
>>
>