Yes it is. All freqs derived from the master OSC input with
dedicated PLLs. BFO can be tuned in 10Hz steps +/- 8000Hz. Some
RA1792 radios have 1Hz RF tuning steps (not mine), but don't know if
the BFO does likewise on those models.
Can't lock the SDR-IQ yet as it needs a 66.66666MHz clock and haven't
yet got round to making a locked clock source for it. Easiest
solution may be an Si570 device - need to investigate.
Andy G4JNT
www.g4jnt.com
2009/1/3 Graham <[email protected]>:
> Andy,
>
> Is the bfo on the ra1792 synthesised ? it is on my ra6790gm , but the
> trusty ra1778 (I have to say that or it develop some obscure fault) has a
> free tune 1.4 mhz bfo .so no good for hyper stable data ! .. but phase
> locked 1.4 mhz cio .....or if you have a pilot tone you can lock onto that
> ... follows 80 mtr am nicely and resolves as ssb .. cheating i know !
>
> I tend to announce,
> dial frequency,
> mode -usb
> software marker frequency ..
>
> multipsk has a centre frequency mark which is handy ..!
>
> Hope the run was of intrest ,
>
> Graham ..
>
>
>
> --------------------------------------------------
> From: "Andy Talbot" <[email protected]>
> Sent: Saturday, January 03, 2009 2:37 PM
> To: <[email protected]>
> Subject: Re: LF: Re: Low power olivia beacon 503 khz cent freq
>
>>
>> If you have a radio with adjustable CW mode like most SDRs, and the
>> RA1792, its easier to use CW mode. Tune to the centre frequency of
>> interest, set the filter appropriately and the BFO to the decoders
>> preferred tone.
>>
>> For last nights listening, my SDR-IQ was set to CW mode, audio lower
>> freq 400Hz, upper freq 1600Hz, BFO 1000Hz
>>
>> (You can set arbitrary upper/lower linits on the SSB filter as well on
>> Spectravue), but guess who initially fell foul of seeing 503kHz
>> specified and assumed it meant the same as the JT65A freq the other
>> night. So, on seeing the tones not where they 'should' have been and
>> re-reading the email post...
>>
>> Must get round to writing a WSPR PIC routine for the AD9852 DDS
>> similar to my existing JT65 beacons.
>>
>>
>> Andy G4JNT
>> www.g4jnt.com
>>
>>
>>
>> 2009/1/3 Graham <[email protected]>:
>>>
>>> Tx bandwidth and out of band signals ,
>>>
>>> Well after picking up the toys from around the cot and tidying up the
>>> baby
>>> finally fell asleep ,silence finally ensued, a little familiarisation
>>> with
>>> the way the radio works may help, just because the rx dial displays a
>>> frequency out side the allocated band, doesn't actually mean the signal
>>> is
>>> out side the band .. its all to do with filter shape factor and the
>>> placement of the filter .... bit like dougle asking farther ted, are all
>>> the
>>> cows in the field the same size as his little plastic toy one... no
>>> dougle,
>>> this ones in your hand and those are far away , right ted came the quick
>>> reply .from a still confused dougle .
>>>
>>>
>>> --------------------------------------------------
>>> From: "mal hamilton" <[email protected]>
>>> Sent: Friday, January 02, 2009 7:54 PM
>>> To: <[email protected]>
>>> Subject: LF: Re: Low power olivia beacon 503 khz cent freq
>>>
>>>>
>>>> OM
>>>> Your transmission is outside the band limit, spreading to 504.6 khz.
>>>> I can see why OFCOM are concerned about stricter control concerning data
>>>> mode bandwidth.
>>>> g3kev
>>>>
>>>> ----- Original Message ----- From: "Graham" <[email protected]>
>>>> To: <[email protected]>
>>>> Sent: Friday, January 02, 2009 6:30 PM
>>>> Subject: LF: Low power olivia beacon 503 khz cent freq
>>>>
>>>>
>>>>> Olivia 1 khz x 32 tone
>>>>>
>>>>> centre frequency 503 khz
>>>>>
>>>>> tx mode usb
>>>>>
>>>>> power 30 watts tune signal
>>>>>
>>>>> Will send for next few hours
>>>>>
>>>>> Reports welcome
>>>>>
>>>>>
>>>>> Graham
>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>>
>>>> --------------------------------------------------------------------------------
>>>>
>>>>
>>>>
>>>> No virus found in this incoming message.
>>>> Checked by AVG - http://www.avg.com
>>>> Version: 8.0.176 / Virus Database: 270.10.2/1871 - Release Date:
>>>> 1/1/2009
>>>> 5:01 PM
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>>>
>>>> No virus found in this incoming message.
>>>> Checked by AVG - http://www.avg.com
>>>> Version: 8.0.176 / Virus Database: 270.10.2/1871 - Release Date:
>>>> 1/1/2009
>>>> 17:01
>>>>
>>>
>>>
>>>
>>
>>
>
>
>
>>
>> No virus found in this incoming message.
>> Checked by AVG - http://www.avg.com
>> Version: 8.0.176 / Virus Database: 270.10.2/1872 - Release Date: 1/2/2009
>> 13:10
>>
>
>
>
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