swl problem

Tony Hateley

while operating in digi mode on 28,140,i tune flex 6500 says success with my longwire,but when I send the swl meter goes off scale,anyone got ideas

Ken - NM9P

If you have set the TX bandwidth to something narrow, in order to reduce the possibility of audio spurs, and the CW offset tone places the "carrier" outside that TX bandwidth, then the rig cannot generate a signal to tune it.  It will go through the tune steps and report a match because it doesn't detect any reflected power (or forward power either)  and thinks the SWR is good.

I solved this by creating a TX profile for the different DIGI modes and setting the CW offset so that it matches the "sweet spot" of the digital mode, or at least lies within the TX filter spread.

Hope this helps.

Ken - NM9P

Tony Hateley

surly that means it should do it on all bands whitch it does not only 10m

Ken - NM9P

Sorry, I didn't understand that this was a single band problem. In that case I would check grounding/RF issues. You may have a situation that is ok when tuning with ten watts, but at full power things go haywire. Also check again that your ten meter Digi setup doesn't have things set up the way I previously described.

Ken - NM9P

Btw... How is your longwire configured to the rig? What length, feed line, and grounding system are you using?

Tony Hateley

its a 66ft longwire with 9.1 balum with feedline of maybe10mts of coaxial cable been using this setup for a year and more everything works fine on all bands in am usb lsb

Tony Hateley

was working fine earlier today just started doing it

Tim - W4TME

That is a very important piece of information.  I would first suspect a change in your antenna system.  There could be some wacky impedance now at that frequency range that is messing with the SWR bridge.

Luis del MOlino

Your ten meters coaxial line is resonating on 10 meters and it is taking RF as a receiving antenna capting RF on the outside of the coaxial line. Try to breaak this resonance with a current balun as MFJ-915 with plenty of berrite beads inseide that will avoid RF to circulate outside of the coaxial cable. This will destroy the resonance of the coaxial and it will avoid RF to circulate trhoug your rig, and power system.

Luis EA3OG