If you want an HF radio that reads to a Hz, ready made, get a used HP (Agilent) 3486 Selective Level Meter. It covers essentially DC to either 20 or 30 MHz. It has a good internal ovenized oscillator, and can be locked to an external standard.
A virtually unique feature is that it will lock onto a carrier and read that carrier frequency to a Hz or better. They are often abailable for a few hundred. The 3486A & B are similar. FWIW, -John ===================== > I have been involved with many kinds of radio receivers for over fifty > years -- amateur, military, and commercial. This modified SDR-IQ is a > dream come true. When I was a young ham, I dreamed of the day when I might > have a receiver that would read out to one kilocycle (before we used the > term Hertz). Now I have assembled one that reads out to one Hertz and is > accurate to a few millihertz -- and thanks to GPS -- it will maintain this > accuracy as long as the GPS satellites keep working. > > I well remember the early radios that I used. I had to be very careful to > not bump the table where the radio was or it would jump completely off > frequency. Whatever frequency it indicated was only approximate. It made > me nervous to operate near a band edge. > > Dave Powis, G4HUP designed and built a 66.66666 MHz DFS for me. I really > appreciate his help on this project, especially since several hams told me > it couldn't or shouldn't be done. Some said that the frequency read-out on > the SDR-IQ would not be accurate because the time-base in the computer's > sound card would be a variable factor, but this is not true. The frequency > accuracy and stability of this radio ONLY depends on the 10 MHz oscillator > in the Trimble Thunderbolt and that oscillator is locked to the GPS > constellation. > > Dave and I worked together on this project for about one year. The DFS box > travelled across the Atlantic Ocean five times before we finished. > > Dave has written an article "Precise Frequency Locking for the RFSpace SDR > radios" and I have a web page showing how I connected all of this > equipment together. Here are the links: > > http://www.braddye.com/g4hup_dfs.html > http://www.braddye.com/gps_do.html > > 73s > > Brad Dye, K9IQY > ex KN9IQY, KN4BK, KM5NK, WB4JCF, ZP5TQ, WA4VXU, WA9RVL, HH2FJ /TI2, /9Y4, > /6Y5, /KP4 > 53 years as a FCC licensed amateur radio operator > 37 years as a FCC licensed first class commercial radio operator > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.