Fw: [wsjtgroup] channel 5.358500 is dead on 60m

[David Tanks]

More info on the power restriction on Ch. 3.

David AD4TJ

----- Forwarded Message -----

From: Jim K6OK via groups.io <jvarn359=gmai...@groups.io>

To: "wsjt...@groups.io" <wsjt...@groups.io>

Sent: Monday, February 16, 2026 at 11:48:46 AM EST

Subject: Re: [wsjtgroup] channel 5.358500 is dead on 60m

Many hams are misunderstanding the new 60m power limit !!

 

In law, the actual limit is 15 watts effective isotropic radiated power (EIRP).  That's 15 watts at 0 dBi.  For a theoretical dipole in free space with 2.15 dBi gain, the 15 watts equates to 9.15 watts.  That's where that number comes from.  No one has a free space perfect dipole on 60m, so 9.15 Watts is NOT the correct power setting!

 

The right way to set your power is to analyze your antenna.  For 60m I use my 160 meter inverted L at 58 ft high with several 100 ft radials.  On 60m it presents an SWR of 4.5.  Antenna modeling shows for 60m a max gain of about 0.6 dBi -- assuming a perfect match at the feed point.  After taking SWR mismatch and coax loss into account, it works out to about -0.5 dbi.  Therefore I set my rig's power output to 18 watts.  That gets me to the equivalent of 15 watts at 0 dBi, in full compliance with the rules.

 

If you're running a lossy antenna, like an end fed wire at only 30 ft up, if you do the calculations you'll find you are legally entitled to run quite a bit more power than 9.15 watts.

 

73 Jim K6OK

 

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