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Old December 4th 04, 04:50 PM
Richard
 
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Default Which digital readout receivers always show the carrier frequency no matter what mode?

I mean your receivers for the hobbyist, not professional. Kenwood R5000. Any
more?

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Old December 4th 04, 05:43 PM
Volker Tonn
 
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Richard schrieb:

I mean your receivers for the hobbyist, not professional. Kenwood R5000. Any
more?


The NRD-525 can do it with a little trick. I bet the 535 and perhaps
others can do it too.
This RX has a BFO to tune the listening tone of a CW-signal only. This
is set to 800Hz in top position but you can vary it to at least
pus/minus 1.5 khz. So setting it to zero beat on the carrier frequency
is not a big deal.

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Old December 4th 04, 07:11 PM
DesignGuy
 
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"Volker Tonn" wrote in message
...


Richard schrieb:

I mean your receivers for the hobbyist, not professional. Kenwood R5000.

Any
more?


The NRD-525 can do it with a little trick. I bet the 535 and perhaps
others can do it too.
This RX has a BFO to tune the listening tone of a CW-signal only. This
is set to 800Hz in top position but you can vary it to at least
pus/minus 1.5 khz. So setting it to zero beat on the carrier frequency
is not a big deal.


Ok, I'm a little confused here. I thought the carrier frequency of a CW
transmission was where the was *no* tone. Otherwise, how would you know if
they were transmitting on 6999.2 or 7000.8 KHz (assuming zero beat at 7000
KHZ)? Either freq would give you an 800 Hz tone.

My NRD-525 did it, though there may have been an offset that could be
changed. I've since sold it so can't verify. I suspect the NRD-535 does
also. My Drake R8B also zero-beats in all modes by default. The Icom R-75
does NOT do this in CW mode, you can only adjust the offset between 300 and
900 Hz.

There is another thread relating to this a bit further down called "What GC
SW radio would you buy for about $1500".




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Old December 4th 04, 07:56 PM
Mark Zenier
 
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Default

In article ,
Richard wrote:
I mean your receivers for the hobbyist, not professional. Kenwood R5000. Any
more?


Unless you're using a synchronous detector that provides a oscillator
signal that the digital stuff can measure, there's no way. From the
point of usefulness you'd want either the equivalent BFO frequency,
or the frequency at the center of the bandpass filter. One is useful
for SSB and RTTY, the other for CW. And for AM, either one, depending
on how you use it.

Mark Zenier Washington State resident

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Old December 5th 04, 01:02 AM
Volker Tonn
 
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Default



DesignGuy schrieb:

Ok, I'm a little confused here. I thought the carrier frequency of a CW
transmission was where the was *no* tone. Otherwise, how would you know if
they were transmitting on 6999.2 or 7000.8 KHz (assuming zero beat at 7000
KHZ)? Either freq would give you an 800 Hz tone.



Why beeing confused?
CW carrier _is_ "no tone". It's your choice tunig the BFO up or down to
make it listenable.
When listening to CW in LSB or USB mode tunig to "no tone" the SSB
offset is defined on 1.5khz. The 525 is able to switch this offset back
to allways show the carrier frequency. Tuning to "no tone" on the 525 in
CW-mode and the BFO in middle/top position shows you the carrier
frequency. You have to "detune" the radio by 800Hz up or down for having
the "listening tone" of 800Hz on this position. Otherwise you have to
tune the BFO.
IIRC CW decoding is allways done in USB mode technically for
historically reasons. At least the NRD-525 does it this way. Military
and marine SSB transmissions are commonly in USB also below 10Mhz.



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Old December 5th 04, 01:14 AM
DesignGuy
 
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Default


"Volker Tonn" wrote in message
...


DesignGuy schrieb:

Ok, I'm a little confused here. I thought the carrier frequency of a CW
transmission was where the was *no* tone. Otherwise, how would you know

if
they were transmitting on 6999.2 or 7000.8 KHz (assuming zero beat at

7000
KHZ)? Either freq would give you an 800 Hz tone.



Why beeing confused?
CW carrier _is_ "no tone". It's your choice tunig the BFO up or down to
make it listenable.
When listening to CW in LSB or USB mode tunig to "no tone" the SSB
offset is defined on 1.5khz. The 525 is able to switch this offset back
to allways show the carrier frequency. Tuning to "no tone" on the 525 in
CW-mode and the BFO in middle/top position shows you the carrier
frequency. You have to "detune" the radio by 800Hz up or down for having
the "listening tone" of 800Hz on this position. Otherwise you have to
tune the BFO.
IIRC CW decoding is allways done in USB mode technically for
historically reasons. At least the NRD-525 does it this way. Military
and marine SSB transmissions are commonly in USB also below 10Mhz.



That's what I thought... thanks.




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