60 Meters for dummies
Do I understand where the CW transmission actually is (600 Hz above dial frequency)? Please explain. USB - set VFO to the lower edge of the "channel (1500 Hz below center frequency). Giving audio emissions from 300 to 3000 Hz above that. K3 and CW - on my waterfall (in HRD) the trace made by my CW transmission is at the (+)600 marker above the bottom of the waterfall. This is where I conclude the transmission actually is, resulting in the 600 Hz tone above where I am actually tuned. Now, do they want this actual +600 Hz transmission in the center of the channel? Or do they want us to tune to the center of the band and transmit 600 Hz above that? If they are tuned to the lower edge of the band do they want to hear a 2100 Hz tone (with us tuned to the center frequency) or do they want to hear a 1500 Hz tone (with us tuned 600 Hz below center frequency)? On PSK31 - Do they want us to tune to the bottom of the channel and then transmit only a single signal directly on the 1500 Hz marker? There would be room for many others as well without exceeding the bandwidth allocated to us. And what is this "data using PACTOR-III technique"? (http://transition.fcc.gov/Daily_Releases/Daily_Business/2011/db1118/FCC-11-171A1.pdf) Somebody please straighten me out. 73, de Jim KG0KP ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
> Do I understand where the CW transmission actually is (600 Hz above dial
> frequency)? Please explain. If XIT and SPLIT are off, the K3's CW transmit frequency is the displayed VFO frequency. The users desired CW pitch frequency is set with the K3's PITCH setting. If the received CW pitch frequency matches the PITCH setting, then the VFO will indicate the other stations transmitted frequency. NOTE: Switching between the K3's CW and CW-REV (ALT button) will result with no pitch change if the receiver VFO frequency display is set to the other station's transmit frequency. Test: tune to WWV at 10.000.000 MHz, CW mode, 50Hz BW. If the K3 is aligned, switching between CW and CW-REV will result with no pitch frequency change. (My K3 requires a setting of 10.000.002 to achieve the no pitch change condition, indicating that my K3's frequency alignment is 1Hz off.) To comply with the 60M FCC statement "For CW emissions (emission designator 150HA1A), the carrier frequency is set to the center frequency." with a K3, set SPLIT and XIT off and set the VFO to 5332, 5348, 5358, 5373, or 5405 kHz. Assuming the other station is complying with the same rule, on the K3 with RIT off, the received pitch frequency will be the K3's PITCH setting. The received pitch frequency is fully the operator's discretion by adjusting the receiver BFO frequency offset setting. For the K3, with the PITCH setting. John KN5L ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
In reply to this post by hf4me
Jim wrote:
> Do I understand where the CW transmission actually is (600 Hz above dial > frequency)? Please explain. No. As Don pointed out, most modern transceivers always show transmitter carrier frequency in the display. On USB and LSB, that will also be the receiver carrier frequency. On CW, however, if the receiver functions in USB mode the receiver carrier frequency will be shifted BELOW the transmitter carrier frequency (always shown in the display) by the offset (pitch) being used. The receiver carrier frequency is *never* actually shown in the display while in CW mode. (I don't know if the K3 allows the option of using the receiver in LSB mode for CW mode. If so, then this whole discussion would need changes to take that into account if the LSB-CW option is being executed.) For examples in the discussion below, I'll use the new 60m channel of 5358.5 kHz (center), or 5357.0 (carrier), as defined in section 97.303(h). > USB - set VFO to the lower edge of the "channel (1500 Hz below center > frequency). Giving audio emissions from 300 to 3000 Hz above that. Correct. Put 5357.0 in the display. That's all that's needed in USB mode. Do the same for Data and RTTY transmissions (including PSK31), using USB mode. > K3 and CW - on my waterfall (in HRD) the trace made by my CW transmission is > at the (+)600 marker above the bottom of the waterfall. This is where I > conclude the transmission actually is, resulting in the 600 Hz tone above > where I am actually tuned. All true. But on CW, your receiver's carrier frequency is NOT the frequency shown in the K3 display. On CW only, the receiver carrier frequency is BELOW the transmitter carrier (and displayed) frequency by the amount of your pitch offset...0.6 kHz for you. If the K3 shows 5358.5 kHz on CW, your receiver carrier frequency is 5757.9 kHz, USB. > Now, do they want this actual +600 Hz transmission in the center of the > channel? Yes...but leave out that "+600 Hz" part. More precisely, your transmitted CW signal **must** always be ON the channel center frequency. Set the dial for 5358.5 kHz in CW mode. > Or do they want us to tune to the center of the band and transmit 600 Hz > above that? Definitely not! To do so would place you 0.6 kHz too high (5359.1 kHz) above the correct frequency (5358.5 kHz). Plus, since the K3 ALWAYS shows transmit carrier frequency, you must have the display showing 5359.1 in order to transmit 600 Hz above the channel center frequency. In that case, your receiver's carrier frequency is 5358.5 kHz, but that's not what you want. (By "band", you mean "channel".) > If they are tuned to the lower edge of the band... > ...do they want to hear a 2100 Hz tone (with us tuned to the center frequency) No. Dump that whole line. > ...or do they want to hear a 1500 Hz tone... If "they" had a receiver in USB mode tuned to the channel's *carrier* frequency of 5357.0 kHz (defined for phone, data, and RTTY modes), then your CW signal on the correct frequency of 5358.5 kHz would produce a 1500 Hz tone in their receiver. > (with us tuned 600 Hz below center frequency)? Establishing your CW transmission on the channel center frequency (5358.5 kHz) means that will be what is shown in the K3 display. But on CW, the carrier frequency of your receiver will NOT be what's in the display, but rather what's in the display minus your CW offset. So, your receiver's actual USB carrier frequency will be 5358.5 kHz - 0.6 kHz = 5357.9 kHz, or 0.9 kHz ABOVE the channel's specified carrier frequency of 5357.0 kHz. But there's no real significance to that. The rules don't care where your receiver carrier frequency is...only you do, for the desired sidetone pitch. Someone who liked an 800 Hz pitch would have his receiver carrier frequency set at 5357.7 kHz. Just make sure on CW that the channel center frequency is shown in the display. That always shows transmitter carrier frequency. Everything else will turn out all right. > On PSK31 - Do they want us to tune to the bottom of the channel and then > transmit only a single signal directly on the 1500 Hz marker? There would > be room for many others as well without exceeding the bandwidth allocated to > us. No. The new section 97.303(h) says in part "...control operators of stations transmitting phone, data, and RTTY emissions (emission designators 2K80J3E, 2K80J2D, and 60H0J2B, respectively) may set the carrier frequency 1.5 kHz below the center frequency as specified in the table..." You must use USB to transmit your PSK31 (60H0J2B) signal, and you "may" set the USB transmitter carrier frequency 1.5 kHz below the channel center frequency. The channelized mode of operation means that most hams will use fixed frequencies stored in memory rather than a VFO, so putting any phone, RTTY, or data transmission on that suggested carrier frequency would seem prudent, even if it can be argued that the rule allows the USB carrier frequency to be below the channel center frequency by less than 1.5 kHz, as no doubt PSK31 could easily accomodate without exceeding channel bandwidth limits on the high side of the channel. > And what is this "data using PACTOR-III technique"? There are discussions and references to PACTOR-III starting on page 6 of the document at: http://transition.fcc.gov/Daily_Releases/Daily_Business/2011/db1118/FCC-11-171A1.pdf It's not something most hams are likely to use, but that might be useful in some emergency traffic situations with non-ham stations. > Somebody please straighten me out. That's my best attempt. 73, Mike / KK5F ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
In reply to this post by hf4me
Mike,
A couple of corrections: 1. In CW, the K3 normally uses LSB. CW-REV is USB. This makes no difference to the recommendation (in CW or CW-REV, just tune the K3's dial to the channel center). 2. In RTTY using either FSK D or AFSK A, the K3's dial displays the RTTY Mark frequency (the higher of the two transmitted frequencies). Therefore, for an RTTY signal to be exactly centered in the channel, the K3's dial should be set 85 Hz above the channel center frequency in these two modes. Just as for CW sidetone, the choice of audio tone pairs is immaterial in either FSK D or AFSK A, provided the software (or TU) and the radio are both set to use the same tones. Using DATA A, on the other hand, the dial displays the suppressed carrier frequency (DATA A is USB). One way to send AFSK RTTY on the channel center using DATA A would be to set the K3's dial to the channel carrier frequency and the audio RTTY tones to 1415/1585 Hz ("Reverse" for MMTTY users, since MMTTY assumes the radio is in LSB). This is not one of the standard tone pairs that MMTTY provides, so MMTTY users would have to enter a "custom" Mark frequency of 1415 Hz. Alternatively, if they wanted to use a standard audio tone pair, users would have to work out the correct dial setting for each channel depending on which tone pair and sideband (DATA A = USB, DATA A-REV = LSB) they preferred to use. 73, Rich VE3KI ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Free forum by Nabble | Edit this page |