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On Dec 13, 2019, at 20:40, Bill Meara via Groups.Io < n2cqr@...> wrote:
Interesting topic. I guess I'm just more accustomed to having the rig display the TX freq and shift the RX to make it audible.? ?But in uBITX CWU and CWL the display is the RX freq with the TX freq shifted.? So tonight I'm in CWL and I hear SKCC stations at 7.0557.? They are really at their normal spot at 7.0550.? ? I call them.? They hear me because my transmit freq has gone down to theirs.? So it all works but it is just a bit different. Actually I'm a lot more accustomed to setting up SSB rigs -- on all my rigs the display freq is where the carried would have been -- LSB extends down from there, USB up from there.? Easier.? ?Setting up CW offset with a Direct Conversion receiver is also a bit of a challenge:? If you are tuning to the high side of zero beat you need your TX frequency to drop down by 700 Hz or so.? This is how it works in a Heath HW-8.?
I understand it is possible to change the display in the uBITX so that it shows transmit frequency.? But this may involve some painful (for me) wrestling with the Arduino IDE, Memory Manager and the new CEC software.? So I may leave well-enough alone.? Unless someone can tell me how to do this EASILY.?
Here is a good discussion of the problem we've been talking about:?
And here is an ARRL forum discussion that talks about how different manufacturers handle this.? ?
I¡¯ll have to look back at the code to see how the MicroBitx ?works, ? But after dealing with this at last field day, I wrote a document on how my ICOM works.
It may not be quite what you thought!
(and I¡¯m pretty sure that¡¯s how my Heathkit SB 102 always worked )?On the ICOM also, when you transmit, you weren¡¯t transmitting zero- beated with your dial frequency. ? As I explained earlier, you would not want to be. ? It¡¯s all a matter of understanding how your rig works?
I¡¯ll go back and look at the code on the uBitx and see how it works. ? Hi,I have always preferred my dial to show my my TX carrier frequency whether or not it is suppressed. There are fiducial marks to show where to set for receive (USB or LSB). WWV is double sideband, full carrier AM (not SSB or CW) and yes it will be zero beated when you are zeroed with it's carrier. SSB and CW require a tiny amount more effort. If you operate near the (sub)band edge pay closer attention.Transceivers are more often setup for the dial to to show the center of the SSB passband and often considered to 1500 Hz from the (suppressed) carrier.In the end, you have to know how the radio you are using is configured. Either way (tx or rx reading) will work but if you are not aware which way your radio works you could transmit outside your license assignment. Your entire emitted signal is supposed to remain inside those prescribed band edges.Merry Christmas and..73,Bill ?KU8HOn 12/13/19 5:34 PM, Gordon Gibby wrote:When I get a chance, I'll check one of my icom's and see what I do, but I suspect many rigs work?exactly this way, so that it becomes easy to be right on frequency?of the other station, and also hear WWV zero beat precisely at 10.000000 MHz.? ?If they worked some other way, WWV would not zero beat at 10.000000, or alternatively you would not be transmitting on the same frequency as the CW station?you had put in the ccenter of your audio filter passband.
On Fri, Dec 13, 2019 at 5:24 PM Gordon Gibby via Groups.Io <docvacuumtubes@... <mailto:[email protected]>> wrote:
???well, you might be right, but when you zero beat a heathkit to a 100
???kHz marker, and subsequently tune in a CW signal, you will be
???transmitting on a DIFFERENT frequency from what your dial shows. ??????So I don't think you are correct for a heathkit SB-102, which I used
???for many many years....and still have
???On Fri, Dec 13, 2019 at 5:11 PM Bill Meara via Groups.Io
???<n2cqr@... <mailto:[email protected]>> wrote:
???????Usually the freq readout on the display IS the transmit
???????frequency, with the offset taking place in the receiver -- the
???????receiver shifts the 700 Hz or so.? ?But here the transmit
???????frequency shifts.? That is kind of weird.? ?As Vic points out:
???????I just finished my V4 uBitX with CEC 1.10 firmware and the V3
???????Nextion GUI. I think the method of offsetting the transmit
???????frequency is backwards to how CW offset should be done. Although
???????this works, it can have bad consequences. If the other station
???????is transmitting on 14.100 I will not hear him unless I tune the
???????uBitX to 14.099300 if I am particular about hearing a 700Hz tone
???????and I am using CWU, so that means I actually will be
???????transmitting on 14.100 when I send back and he will hear me.
???????Similarly, if I have selected CWL I won¡¯t hear him until I set
???????the receiver to 14.100700 and I will be transmitting back on his
???????frequency. However, we should be indicating the actual transmit
???????frequency, not where I have offset to hear the other station. If
???????I was close to the lower band edge, and I wanted to call CQ on
???????14.000500, I would actually be transmitting 200Hz below the band
???????limit if I have selected CWL mode. Other rigs I have used, even
???????Allard¡¯s sketch for the BitX40, offset the receiver by the
???????amount of the desired tone (offset), either up or down based on
???????if CWU or CWL is selected, so the transmitter always is sending
???????on the dial frequency.
???????On Friday, December 13, 2019, 04:38:21 PM EST, Gordon Gibby
???????<docvacuumtubes@... <mailto:docvacuumtubes@...>> wrote:
???????So, when you do CW, you don't zero beat your RECEIVER to the
???????other station, do you?
???????No.
???????You dial your receiver just the right amount off from the other
???????station's zero beat so that either (a) you are set so that your
???????transmitter will be on the other station's frequency?and you can
???????hear a nice tone from the other station or
???????(b) if you have a very narrow filter, you do (a) as well, but
???????you adjust so that the other station is PEAKED in your passband.
???????Either way.....you are NOT transmitting precisely?where your
???????dial says....because typically you are offset by about 800 Hz.
???????Precisely what you observed.
???????Maybe that makes more sense?
???????My heathkit works the same way.
???????Gordon
???????On Fri, Dec 13, 2019 at 3:57 PM Bill Meara via Groups.Io
???????<n2cqr@... <mailto:[email protected]>> wrote:
???????????I'm trying to get my Version 3 uBITX with CEC version 1.071
???????????to work properly in CW mode.? I have the same problem that
???????????Vic WA4THR had -- I really prefer just to have the display
???????????show the transmit frequency, with the receiver shifting to
???????????produce the desired CW tone.? That is not what happens under
???????????ver 1.071.? ?When the dial indicates 7.0407, I am actually
???????????transmitting on 7.0399.
???????????Is there anyway I can easily correct this without a major
???????????software overhaul?? I am still running uBITX v 3 with a 16x2
???????????display.
???????????Thanks,? Bill N2CQR
-- bark less - wag more
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