[Elecraft] Legal Limit With FT8

Rick Bates, NK7I rick.nk7i at gmail.com
Thu Nov 11 11:26:24 EST 2021 

On phone or CW, it's a dog fight and power (and antenna gain) often 
reigns supreme.  That's the reality.  Get heard, get worked, get out.  
The JT modes bring something new to the playing field; making it more 
'level'.

For many, it's not about the distance or miles/km per watt.  That is 
determined by the magic of radio conditions.  QRP into a light bulb 
filament (not LED), may work stations during the really good cycle peaks 
while in the doldrums one must use a lot more to make the contact.

As Jim rightly says; it's ALL about noise, but keeping your local noises 
to a minimum is only half the equation.  Expanding what he says, when it 
comes to working DXpeditions (taking the latest groups in AF as an 
example), the antennas are not optimal (because they are hauled in/out, 
not on 30 meter high towers with proper grounding, not a permanent 
installation but lashed up); their local site is rarely optimally placed 
(a hotel or beach), the noise floors are frequently very high 
(thunderstorms add more exciting noise) and the power grid is also noisy 
(and intermittent) in some areas. Their output levels are variable due 
to ability or local laws, often not 'generous'.

The end result is that the calling station, generally has ZERO clue 
about conditions at the other end.  One can watch the DX to see the 
reports given and get a sense of their hearing ability (or lack) for 
known big guns being worked; but until the actual contact is made and a 
real report (life isn't always 59) given, one doesn't really KNOW that 
the power was excessive; then it's over.  What YOU hear is not what THEY 
hear; compare equally built stations but pay attention to the NOISE floors.

In some cases, one must surf the waves of QSB too; timing is critical in 
any mode.

Sadly, this is true even on permanent stations, i.e. one on Guam that 
transmits a GREAT 100 watt signal but the noise floor is so high that 
those calling MUST run much higher power to be heard.  Often, it's not 
possible.

However, JT modes also allow those with less than optimal (flea power, 
string antennas) stations to participate more often.  Perhaps not to 
work the rarest of DX, but they're 'in the game' enjoying the hobby.  
That's a HUGE benefit.

Rarely, the reverse is true.  Working the Antarctic stations with their 
noise floor at MDS, their reports are often better than most stations 
calling (I was so shocked that it worked with a meager wire antenna and 
100 watts on 60M [legal EIRP limit in the US], I tried for an 'insurance 
dupe' at half the power just to verify, got it too).  In that case, they 
had to overcome MY local noise, which is pretty good in the rural zone 
I'm in (the same worked on CW too and they weren't loud).  [K3's at both 
ends, HAD to help at least a little.  ;-) ]

Don't sweat the output power of others but pay attention to your 
station.  High output doesn't help work stations faster in JT modes 
(which can even be set to ignore loud stations in DX mode) and it 
doesn't usually cause an issue IF it's a cleanly transmitting station 
(KEY POINT), even when on the same tones as others (I've seen two 
station on exactly the same tones get decoded, one +4 and the other -18 
dB, the JT modes are magical).

My general rule is to base my output power on the signal level I 
receive, with a sense of their local conditions (based on their 
reports).  If that doesn't work, double the output power (add 3 dB) and 
try again (repeat as needed).  Generally, that works out but not always 
if the DX is in a noisy place.

In a perfect world of no noise, we could all work each other at QRPp 
levels.  Reality is much harsher.

Lower YOUR noise floor and keep YOUR station clean to cause no harm; let 
the other stations do the same.

73,
Rick NK7I




On 11/11/2021 7:17 AM, Lyn Norstad wrote:
> Richard -
>
> As of today, I have worked 40 stations in VK6-land ... the farthest land
> mass area, for me, on Earth.
>
> This is with 50 watts (or less) FT8, mostly on 40 meters, mostly 0800 - 1300
> UTC and, basically, an oversized dipole at about 35 feet (actually a 3.5 MHz
> EDZ - but that's another story).
>
> Included in that bunch is THE station that appears to be the furthest from
> me located on land (a MM in the South Indian Ocean might be farther, maybe).
>
> I gave him a -15, and he gave me a -07.  QRZ distance, 11,026 miles.
>
> 73
> Lyn, W0LEN
>
> -----Original Message-----
> From:elecraft-bounces at mailman.qth.net
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Richard
> Sent: Thursday, November 11, 2021 7:17 AM
> To: Elecraft Mailing List
> Subject: Re: [Elecraft] Legal Limit With FT8
>
> There's a major jerk who lives within about 20 miles of me who runs BIG
> power with FT8. When he's on the air, he blots out my K3S so his is the only
> signal on the waterfall, the only signal the decoder sees. When his BIG
> POWER is on the air, I can't be. And he's made it clear that he doesn't care
> what he does to anyone else's enjoyment. Power for power's sake is
> contagious.
>
> On the other hand, I've made several 10,000 to 11,000 mile Australian
> contacts with 15 watts and a hex beam at 30 feet.
>
> Richard
> W4KBX
>
>
>> On Nov 11, 2021, at 2:17 AM, Jim Brown <jim at audiosystemsgroup.com
> <mailto:jim at audiosystemsgroup.com>> wrote:
>> On 11/10/2021 10:36 PM, Rick Tavan wrote:
>>> I must be missing something.
>> Hi Rick,
>>
>> FT8 and similar modes are weak signal modes, and for difficult paths, it's
> all about signal to noise, not signal to QRM. For several seasons, I've been
> running legal limit to fill in DXCC to eastern EU on 160M. During the
> summer, many of us run legal limit and lots of aluminum on 6M for weak and
> brief multi-hop Es openings to fill in missing grids in search of the Fred
> Fish award. We also run power for meteor scatter, and most who do moonbounce
> run legal limit.
>> The fundamental GOOD reason for power is RX noise on the other end of the
> QSO. I regularly give signal reports 10-15 dB better than I receive, simply
> because most hams are bathed in electronic noise from their own homes and
> those of their neighbors. Noise levels have increased drastically over the
> years. When I first moved to W6 in 2006, I could work EU on CW. Not a lot,
> but at least 3-4 QSOs per year, sometimes more. In the last six years, I've
> HEARD 6 CW signals from EU, and only two heard me. And my 160M antenna farm
> is better today than it was then.
>> 73, Jim K9YC
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