[SCCC] FT8 Power

Tue Dec 4 21:31:24 EST 2018

Good perspective, Art. If you were -11 at 1,000 watts, you theoretically
were -21 at 100 watts. FT8 should generally work down to -24 but in my
experience, not always. Considering that even 3 dB of QSB would potentially
disturb the decoding if you were already at -21, that's possibly why you
guys were no go at 100 watts. A mere 3 dB increase in your output power to
200 watts should have taken you to -18, and surely solid copy on his end.
Once you are above the threshold, you're usually golden.

I've also found that FT8 decodes fine if you are as little as a couple Hz
difference in offset from QRM. Meaning, if a strong station is zero beat
with the other station and you are only 2 or 3 Hz different in offset, he's
going to be able to decode both of you, even if he is +10 and you are -15.
It's crazy that it works that well but that has been my experience. 

-----Original Message-----
From: SCCC <sccc-bounces at contesting.com> On Behalf Of k6xt
Sent: Tuesday, December 4, 2018 10:19 AM
To: sccc at contesting.com
Subject: Re: [SCCC] SCCC Digest, Vol 192, Issue 6

This FT8 power discussion will no doubt go on forever so might as well 
weigh in.

This spring ('18) Kamal 4S7AB and I were FT8 skedding on 80M, a new one 
for me on any mode. Despite QRO on both ends the best we could do was 
copy each other one time, i.e. one 15 second interval. Unfortunately not 
on the same day, so no QSO. With less than QRO, no copy at all. Lets 
face facts. Power works the same in digi modes as it does anywhere else!

Just now I worked 3B8FA on 17M. My ant is nothing special, 3L homebrew 
at 45 ft. At 100W he did not hear me over several calls, enough to 
discount QSB. Up went the watts to about 400 and we had a QSO altho at 
-11 I wasn't blowing his doors off.

There's really no telling until we try how much power will be 
successful. Just before my 3B8FA Q I'd worked 3B9FR and XT2BR on 100W. 
It takes whatever it takes.

On FT8 in general, a case of RTFM. I'd installed the latest 2RC5 but 
didn't pay much attention to the manual. Today QRV on 160M I could only 
print one station W5XZ. After much head scratching and config alteration 
I finally asked the question. Only to learn 2RC5 is incompatible with 
1.xxx which is why I was only printing XZ, he's on 2RC5. Now, since most 
are still not using the latest, its two separate installs of WSJTX.

73 Art K6XT~~
Success is going from failure to failure without a loss of enthusiasm.
ARRL LM, CW OPS, GMCC, MHDXA, NAQCC, NCDXF, SDDXC, CDXC
ARRL TA

On 12/4/2018 10:00 AM, sccc-request at contesting.com wrote:
> Message: 1
> Date: Mon, 3 Dec 2018 19:26:29 -0800
> From: "Jim Price"<jnprice at pacbell.net>
> To: "'Wayne Overbeck'"<overbeck6 at yahoo.com>
> Cc: "'SCCC'"<sccc at contesting.com>
> Subject: Re: [SCCC] Is 50 watts enough?
> Message-ID:<000e01d48b81$26698a80$733c9f80$@pacbell.net>
> Content-Type: text/plain;	charset="us-ascii"
>
> I generally run "barefoot" on FT8 HF, except on 80 meters when I'm working
> Europeans.  I only have a KPA500, so I'm not exactly burning a hole in the
> ionosphere!
>
> On 6 meters, I run the amp on meteor scatter (MSK144).  On FT8, it
depends.
> If the band is really open and sounds like 20 meters (which it did many
days
> last summer), I'll run barefoot.  If signals are marginal, or I'm trying
to
> work DX, then on goes the amp.
>
> I think it's judgement call.  In my opinion, if a W6 is on, say 20 meters,
> trying to work a guy in, say Illinois, and the signals are +10 both ways,
> then please do NOT run an amp!!
>
> 73 - Jim K6ZH
>
> P.S. boy, would I like to work 100 grid squares in EU on 6 meters!  Right
> now I'd settle for 1;-)
>
>
>
>
> ------------------------------
>
> Message: 2
> Date: Mon, 3 Dec 2018 20:51:18 -0800
> From: "Wolf Leverich, WA6I"<leverich at mtpinos.com>
> To: Wayne Overbeck<overbeck6 at yahoo.com>
> Cc:sccc at contesting.com
> Subject: Re: [SCCC] Is 50 watts enough?
> Message-ID:<20181204045117.GA20694 at cap-75.linkpendium.com>
> Content-Type: text/plain; charset=us-ascii
>
> On Tue, Dec 04, 2018 at 03:06:23AM +0000, Wayne Overbeck via SCCC wrote:
>
>> On this reflector I suspect both of those viewpoints would have
defenders.
> And it may be changing with time.
>
> Almost a year and 10,000 QSOs ago, I could do a*lot*  with QRP power
> or a bit more.  It was unusual for me to operate with more than 35W.
>
> Last summer and 5,000 QSOs ago, I could do a*lot*  with 80W.
>
> Right now, I'm shifting to my "usual power" being 200-400W on 20 and
> below during "peak hours".
>
> And propagation really isn't the problem -- it's too much success with
> a nonscalable solution.  There are 50 gazillion people doing FT8 these
> days, which means there are about 5 gazillion alligators and straight-up
> LIDs or worse.
>
> And they are all packed within less than 3 KHz of spectrum on each band.
> When bands are crowded, you have to be loud these days or a ustabe CBer
> with a linear will plop right on top of you, either because he can't hear
> worth beans or he just doesn't care.
>
> Dunno what the wSJT team is doing right now -- I'm behind the times --
> but one of the screaming silly problems that needs to be addressed is
> having more FT8 spectrum space even if many rigs aren't going to be
> able to see more than 2.7 KHz or some such at a time.
>
> Otherwise, a really great mode for little pistols is going to get so
> crowded that only the guys with a lot of often-otherwise-unnecessary
> decibels from their amps and yagis are gonna get heard.
>
> 73 de Wolf WA6I

_______________________________________________
SCCC mailing list
SCCC at contesting.com
http://lists.contesting.com/mailman/listinfo/sccc