> On Dec 2, 2020, at 9:23 AM, William Hein <b...@soundbusiness.us> wrote: > > Back to the phase locked receivers in the K4D. Does the K4HD retain this > feature? I am wondering if the Superhet circuitry would mess up the phase > coherence?
The HDR (superhet) module is phase-locked at the IF. At the LO injection it's frequency-locked to a small fraction of a Hz. This results in very slow (mutliple-second) phase precessing when using diversity mode, which in our experience has no impact, given that atmospheric phase changes occur much more rapidly. > ...is there a way to bypass the K4HD Superhet circuits when not (for example) > operating in a HF contest M2 or MM? Yes. There will be a top-level control for this purpose. 73, Wayne N6KR > > 73 > Bill AA7xT > > > Bill Hein > Sound Business Strategies, LLC > m 970-628-5120 > b...@soundbusiness.us > > > > The information contained in this transmission may contain privileged and > confidential information, including patient information protected by federal > and state privacy laws. It is intended only for the use of the person(s) > named above. If you are not the intended recipient, you are hereby notified > that any review, dissemination, distribution, or duplication of this > communication is strictly prohibited. If you are not the intended recipient, > please contact the sender by reply email and destroy all copies of the > original message. > > Please help reduce paper and ink usage. Print only if necessary. > > > On Sat, Nov 21, 2020 at 5:53 PM Wayne Burdick <n...@elecraft.com> wrote: > Then yes, this should work. I had assumed it was producing a 1-Hz square > wave. > > Wayne > > ---- > elecraft.com > >> On Nov 21, 2020, at 3:20 PM, William Hein <b...@soundbusiness.us> wrote: >> >> >> Hi, Wayne! >> >> I'm very happy about the phase sync between the two rxs, that will be a lot >> of fun! >> >> FYI - The Bodnar GPS unit outputs a programmable output including 10 MHz at >> various levels: >> >> Low-jitter GPS-locked precision frequency reference >> 450 Hz to 800 MHz output >> This device outputs two synchronised low-jitter reference clocks locked to >> GPS signal. >> Long term stability of output signal is defined by high accuracy of GPS >> Caesium references and theoretically approaches 1x10-12. >> Short term signal quality is defined by internal TCXO clock source providing >> high-quality, low phase noise clock signal with sub-picosecond RMS jitter. >> Digital PLL allows main output reference frequency to have almost any value >> between 450Hz and 800MHz. >> The second output frequency depends on the first output due to a common >> internal clock, if you need individual flexibility, multiple mini GPS units >> may be a better choice. If both outputs have the same frequency their >> relative phase shift can be adjusted. This can be used, for example, to >> generate two signals with 90° phase shift for use in I/Q mixer. >> Both output signals square wave at 3.3V CMOS levels with 50 Ohms >> characteristic impedance. Their output drive levels can be adjusted and >> outputs can be enabled and disabled independently. >> Output power level (measured at 10MHz, fundamental power channel): >> +13.3dBm, drive setting 32mA >> +12.7dBm, drive setting 24mA >> +11.4dBm, drive setting 16mA >> >> Bill Hein >> Sound Business Strategies, LLC >> m 970-628-5120 >> b...@soundbusiness.us >> >> >> >> The information contained in this transmission may contain privileged and >> confidential information, including patient information protected by federal >> and state privacy laws. It is intended only for the use of the person(s) >> named above. If you are not the intended recipient, you are hereby notified >> that any review, dissemination, distribution, or duplication of this >> communication is strictly prohibited. If you are not the intended recipient, >> please contact the sender by reply email and destroy all copies of the >> original message. >> >> Please help reduce paper and ink usage. Print only if necessary. >> >> >> On Sat, Nov 21, 2020 at 2:46 PM Wayne Burdick <n...@elecraft.com> wrote: >> >> > On Nov 21, 2020, at 1:38 PM, William Hein <b...@soundbusiness.us> wrote: >> > >> > The K4D looks like an amazing radio! I am interested in diversity rx, >> > primarily on 50 MHz. A few questions: >> > >> > (1) Are the two K4D receivers phase coherent (in sync)? >> >> Yes. >> >> >> > >> > (2) What is the resolution of the HDMI video output? >> >> Up to 4K. >> >> >> > >> > (3) Will the Ref In work with something like the Bodnar GPS reference >> > clock? >> >> REF IN requires a 10 MHz signal, not a GPS pulse. >> >> >> 73, >> Wayne >> N6KR >> ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
