F6700 measurement

Sergey R5AU

Have some body measure: 1. real CW delay- from key down to RF output ? 2. Noise level on Line Out in compare with others RX, ex: F5000 ? with SSDR 0.13.10

Al_NN4ZZ

Sergey, The CW latency question came up on another topic yesterday. http://community.flexradio.com/flexradio/topics/i_get_random_hiccups_when_using_cw ******************* Mickey posted this *********************** CW (paddle key down to xmit) latency seems higher with the new code (0.13.10) Previous version was similar to KX3 and Icom transceivers, this version is considerably different. I can set it up on a scope and send you traces if you'd like to see it. Keyer set at 22WPM, usually. I suspect now that it is more on the transition between a dah and dit that is a bit too long. If you hold the key to the dit side to send a long string of dits, it skips one after about 30. I know, fix one thing, break something else... Whack-a-mole. 73, ********************* Al / NN4ZZ posted this *************************** It would be interesting to see a trace like the example below showing the latency. Regards, Al / NN4ZZ

Sergey R5AU

Al, i got it, sorry , i have not read topic with CW hiccups. Mean now in 13.10 looks like 15 ms to the full power (pity). I assume it a feedback from the CODEC improvements. i think necessary to escalate this issue for the next CODEC improvement together with full DSP power implementation for RX and TX on expected level for 6700 device

Al_NN4ZZ

Sergey, Just to be clear, the example waveform I posted is NOT for the 6700. A latency of 10 to 20 MS is typical for the test setup shown and used by the ARRL testers. Mickey offered to put a scope on the 6700 to see what he measures. Regards, Al / NN4ZZ

Sergey R5AU

OK Al, clear, i will try to mesure it during the weekend,for such class of the TRCVR it should be maximum like 6-8 ms

Steve-N5AC

Here's what the radio looks like sending dots at 60WPM

Ken - NM9P

Nice! Just for fun, in your "spare" time, can you run one of those graphs at 20 wpm QSK? Or will it look essentially the same? Thanks.

W5XZ - dan

so, from key down to rf out, 8.2 ms? is that invariant with code speed? thinking about adding QSK to my homebrew final, with either PIN diodes or vac relays; does this mean the final will need to switch in less than 8 ms ?? thanks

Sergey R5AU

Thank you Steve, cool, FRS Go Ahead !

K4EAR

From Steve's screenshot it looks like the output relay of an amp (or other external TX1,2,3, acc). would need to switch faster than ~~13ms on break also. The initial RX-TX is covered with the TX delay if needed.

K4EAR

I mean slower than ~13ms, sorry

W5XZ - dan

( whew, you had me going...ha ha! was thinking HUH?? ) from key up, to no rf, you want the amp relay to open before the rig quits transmitting ?? naahhhhh.. 73

Steve-N5AC

You can hold off all of this by adding in tx_delay on the setup panel

W5XZ - dan

so, just set it to 13 or 14 ms? ( IF the amp can keep up...)

K4EAR

The TX delay does not hold off on the break side going back to RX, thus my point. The output relay in a QSK amp would need to hold in until the RF decays from the 6xxx. What I see is 13ms +/- from PTT release to RF decay for 60wpm CW. Maybe splitting hairs here...

K4EAR

If a QSK amp has the smarts to provide a TX enable signal post switching back to the 6xxx, TX REQ, then no worries, a closed loop, and have at it.

K6OZY

Can someone explain to me what all of these settings mean, specifically with use cases? I read the manual and still don't understand when I would use them. My amp is an Elecraft KPA500, which I think doesn't need any timings adjustment since its QSK pin diode. But I'd still like to understand why these are important. TX Timeout is obvious. Thx

Steve-N5AC

RCA TX1, TX2 and TX3 are PTT outputs that may be delayed from the time that the PTT in the radio is depressed. They require pull-ups to operate (they are open collector outputs). TX_Delay says how long from PTT until it is OK to send RF out from the antenna port. If your amplifier takes 15ms to key, you should set this to 15, for example. TX_timeout is just a cutoff in minutes to prevent an accidental mic depress from keeping the radio transmitting for hours. The TX_REQ inputs on the back of the radio is another way to do the same thing -- if you enable them, you can have the radio not product RF output until these are asserted after a PTT

K4EAR

Steve please add a scope channel so we can see the TX out rca out timing in between the keyer PTT and the RF out. Your pick of 0-10ms TX delay setting and CW delay. Let's see the release transition of the rca ptt out and rf decay time screenshot.

K4EAR

http://www.w0qe.com/amplifier_timing.html

Steve-N5AC

Are you looking to be sure that the RF only comes out when the TX1,2,3 lines are asserted? If so, we did a lot of testing on the scope when we worked on this code, but I did not save any of the tests.

K4EAR

NO, delay the PTT outputs until the RF decays.

K4EAR

You have the rx-tx transition covered with any timings needed. Take a look at the reverse and the TX output ports when a tx enable signal collapses, no matter qsk or a simple ptt. There needs to be a "hang" time for rf to decay before the rca ports drop out...

K4EAR

with all deference to the team at Flex, give us an option for better timing outside of the elusive QSK mantra. Don't close the barn door (with timed TX outs) before the horse gets in (Rf decay) with the TX-RX transition. We're in a classical zero-sum game here it seems.

Eric-KE5DTO

I think I understand what you are saying, but can you be explicit using the link you posted above? Which T# are you saying need to be addressed?

K4EAR

It is T #6, look at the second scope shot in the discussion about the Icom7000 and the 706mkIIg. The Hsend line would be the TX outputs on the 6xxx

K4EAR

For the 6xxx look at the timing differences when PTT whatever the mode, transitions from TX to RX vs. the TX output port(s) , vs. the tail -end of RF out. Those bases need to be covered. As I understand it know, the delays afforded for now ONLY effect the "make" side of the equation and cover the bases.With any release of PTT, whether a QSK CW, break-in CW, VOX, MOX, with release of PTT, the TX out switching falls out concurrently with no deference to the tail end of RF out.

Steve-N5AC

We will release the TX signal when we are complete sending RF. In other words we wait for our RF to finish then we unkey our transmitter and release the TX outputs. Do we need to do something different?

K4EAR

That's the ticket, halleluiah. TNX so much!!!

K4EAR

Maybe add an enable /disable checkbox for each port so we can have external stuff connected constantly to the RCA ports. I use the timed Flex TX outs to key opto-SS relays to sink or source voltages for external amps/relays/gear! This was a great option in PSDR 2.6.4, even going back a few years. I certainly appreciate the "ear" so far...