CW1 and CW2 - what's the difference?
- Can anyone tell me what the difference between CW1 and CW2 mode is please? Are there two different filters with different bandwidths?
I couldn't find any information in the manual, but on my rig CW2 doesn't seem to pass any signal - I just get some slight noise?
- CW1 is LSB-SSB mode with the CW audio filter; CW2 is the USB-SSB mode with the CW audio filter. If CW2 mode is dead, what about USB mode? The audio filter is the same one for both CW1 & 2 - iirc, centred at 800 Hz. In effect, when properly aligned, in CW1, you would tune 800 Hz above the carrier while for CW2, 800 Hz below, to get the peak heterodyne from the desired signal.
- As far as I can tell, LSB works OK as I have picked up LSB transmissions on both both 40m and 80m. Hovever I have never picked up anything on 60, 20 or 10m though, so I don't know if USB works.
Does the CW mode follow the same LBS/USB usage per bandwidth as does SSB, i.e. LSB on 160, 80 and 40m, and USB on 60, 20 and 10m?
- Tune the MW band for a local AM station. Switch to LSB and fine tune so that
the heterodyne pitch falls to zero or as close as you can get. At this point
the music and speech should be intelligible and at or near the right pitch.
Switch to USB and repeat. If you cannot tune to get the same results, then
your USB is clearly defective. In all probability, the USB beat frequency
oscillator is not oscillating at all or is badly mistuned. Ideally, but
rarely achieved with the 394, it should switch from zero beat on LSB to zero
beat on USB when tuning a carrier at any frequency in its tuning range.
For listening to Morse Code, you choose CW1 or 2 according to which one
suppresses interference better. If the interferer is higher in frequency,
LSB should work better; USB should be better if the interferer is at a lower
frequency. With Single Sideband voice, only one sideband is transmitted, the
other sideband is suppressed, as is the carrier. While it is possible with
the 394's mediocre filter to demodulate the sideband opposite to the the one
chosen by the mode switch, it works far better for the receiver to be set to
the same sideband as is transmitted. The ham band convention of transmitting
LSB below 10.5 MHz and USB above stems from early transmitter design.
- one is normal CW and the other is narow CW
never forget 09-11-2001
On Sat, Feb 2, 2013 at 2:14 PM, jchajecki <yahoog@...>wrote:
> As far as I can tell, LSB works OK as I have picked up LSB transmissions
> on both both 40m and 80m. Hovever I have never picked up anything on 60, 20
> or 10m though, so I don't know if USB works.
> Does the CW mode follow the same LBS/USB usage per bandwidth as does SSB,
> i.e. LSB on 160, 80 and 40m, and USB on 60, 20 and 10m?
> DO NOT KEEP this message in your reply. QUOTE PARTS ONLY if needed for
> clarity. STOP BALLOONING of message size.
> Yahoo! Groups Links
[Non-text portions of this message have been removed]
- Dave, that is incorrect. CW1 is LSB with the 'narrow' audio filter. CW2 is
USB with the same 'narrow' audio filter. All four use the 394's notoriously
wide SSB IF filter at 455 kHz.
From: dave in maine
Sent: Saturday, February 02, 2013 3:59 PM
Subject: Re: [RADIOSHACKDX394] Re: CW1 and CW2 - what's the difference?
one is normal CW and the other is narow CW
- I tried your suggestion. It tuned OK on LSB as mentioned. Didn't quite get rid of all heterodynes, but still got a low 'rumble'.
Switching to USB the 'rumble' was much louder (had to give it a ver slight one notch tweak) and the audio quieter and dalek-like but it was there.