Michael (GØPOT) @DrOrthogonalIf you’ve ever sent the % sign in CW did you use the letter ‘o’ (o/o) or zeros (0/0)? The latter seems longer but is what I’ve seen documented in a few places.
Personally, I just send PCT to denote that a number is a percentage of something, and I’ve never had anyone ask for a repeat or clarification. But, this made me curious as to what Recommendation ITU-R M.1677-1 (10/2009), International Morse code, has to say about this. The relevant bit is Section 3.3:
3.3 Percentage or per thousand sign
3.3.1 To indicate the signal % or ‰, the figure 0, the fraction bar and the figures 0 or 00 shall be transmitted successively (i.e. 0/0, 0/00).
3.3.2 A whole number, a fractional number, or a fraction, followed by a % or ‰ sign, shall be transmitted by joining up the whole number, the fraction number, or the fraction to the % or ‰ by a single hyphen. Examples: For 2%, transmit 2-0/0, and not 20/0. For 41/2‰, transmit 4-1/2-0/00, and not 41/20/00.
So, for all you purists out there, now you know. It still seems easier just to send PCT, though.
A silver lining?
Perhaps one good thing about the COVID-19 (coronavirus) epidemic is that there seems to be more activity on the ham bands. Last night and Friday night it was easy to make a contact, and there seemed to be more signals on the panadapter than usual. On reddit/r/amateurradio, one ham wrote:
One good thing about the coronavirus in Europe , is that FT8 is absolutely buzzing right now with Italians, French, Germans, and Spanish. 100 contacts so far. Normally make about 30!
Here in Ann Arbor, we’ve started a daily “shut-in” net on the ARROW 2m repeater (146.96 MHz). Several guys have committed to being on the repeater from 7 pm to 8 pm nightly, and more often generally.
IF tap for boat anchors
A couple of days ago, I was chatting with a guy on 40m who happened to be a vintage radio fan. When I mentioned that I was using a Flex 6400, he said that he’d love to have a panadapter, but he doesn’t want to give up his vintage radios. What he’d really like, he said, was an IF tap for his older gear, something like the IF tap that you can get for theFT-450D.
That seems doable to me. Does anyone out there know of such a device for older tube gear?
Dave New, N8SBE says
Re: IF taps
Check out the LP-Pan mailing list at https://groups.io/g/LP-PAN
The LP=Pan can be built for a variety of IF frequencies, and it’s been interfaced with a wide variety of radios, so I’d bet that some of the folks on the list have done it with tube radios.
Hiroyasu Wakamatsu says
KD2C sells such high impedance input buffer board to tap IF for various IF frequencies to match the radio. He just copied G4HUP design. See the following URL. https://kd2c.com/hi-z-tap-boards
He also sells a version without low pass filter to install it before the first mixer. The output does not move when you move VFO dial this way and you can view the whole band if you have SDR with wide bandwidth. You can sync the frequency selection in SDR software with CAT control as well.
I installed both boards into my FT-450D. You can view the documentation from KD2C, the datasheet for the coax I used, and the photos of my installation in my shared Google Drive folder below.
https://drive.google.com/open?id=15EKYa3FlidzscPg4oeHoe8EjuR6YC8yQ
I hope this helps.
73 de AD8AE