What is the proceedure for tuning an antenna?

Am finally plucking up the courage to go for some real talking contacts after a few months of exclusively FT8. I then realised I had no idea on the procedure of tuning an antenna whilst live, is it a case of announcing your call sign in a clear frequency, then manually tuning your antenna, or is there a set procedure? Might be a daft question, but I want to get it right.

Key up a CW signal right over the conversation you wish to join whilst fiddling with the ATU blissfully unaware that your actions are infuriating everyone else!!

Joking quip there but you'd be surprised how often you witness it on air.


On my homebrew ATU I have a set of numbers on the variable capacitors controls and inductor switches with which to reference much like that available on commercial units. I found the settings that were most suitable for a particular band on my particular antenna with the help of a NanoVNA so thoughtfully gifted by a fellow CT member. (Cheers Alan.  ) This handily equates to the lowest SWR reading also but on a matching unit or ATU you could have a couple of 'low SWR' point settings and always good to find the 'best' one. You don't need the help of a NanoVNA as usually the 'best' setting is where you get the best reception of signals you're trying to hear.

I have these 'numbers' typed up on a handy reference piece of paper next to my ATU so that I can quickly set it up whenever I switch bands. This has been done for my own use of FT8 frequencies but I know a little 'tweak' will bring it up to the voice mode frequencies. (You can use the 'tune' button on FT8 software in a clear part of the waterfall to do live transmission tests without annoying anyone.) After a while you stop using the 'reference' sheet and simply remember the settings after doing them for some time. Lands up being much quicker to set up your ATU than most believe, sometimes quicker than the relay clickety-clack of an auto ATU without memory features.

There are bits of kit such as an impedance noise bridge that enable you to 'silently' tune the ATU to a 50 ohm load without transmitting but quite often is more of a faff than doing it without....especially if you forget to switch it out and transmit into it! (I did build my own installed inside my ATU but removed it after finding out it wasn't all that useful.)

I also don't worry about realising a 'perfect' 1:1 SWR knowing that any reading of less than 2 is more than sufficient. (For my own preferences 1.5 is pretty much 'bang-on' or good enough.)

Always good to use low power to setup your ATU so that you don't damage it whilst finding your settings. (Easy at the Foundation 10W limit anyway.) I've seen too many 'burned' or arced out from wildly mismatched QRO shenanigans.


It's often not the finicking procedure most make out Mark, your FT8 settings will be in the ball park and as mentioned a little tweak will have you in the voice mode frequencies. No point tweaking further after that when your RF meter is bouncing about on SSB but as long as the SWR isn't bouncing all will be good. (A low SWR should always be low regardless of power output as it is a ratiometric reading.)

Much easier than you think so don't sweat the small stuff.


Of course there are always 'resources' that will go into intrinsic detail of how to perform an ATU adjustment and if that level of fiddling is your bag then go for it. Otherwise quickly tune up and get yourself on air.   


Not a 'daft' question after all, we all have to start somewhere. Tweak for voice when you're transmitting and all will be well.

Hope that helps Mark, just remember to enjoy yourself.

All the best,
Victor

The procedure is to buy an Auto ATU that remembers each frequency.

Only kidding but it does take the faff out of tuning.

My own is the MAT 1500PRO coupled to the IC7300.
I use it to tune both HF ants when the 7300 cannot reach tune, especially when the cobweb is wet.

Ivy Mike wrote:

The procedure is to buy an Auto ATU that remembers each frequency.

Only kidding but it does take the faff out of tuning.

My own is the MAT 1500PRO coupled to the IC7300.
I use it to tune both HF ants when the 7300 cannot reach tune, especially when the cobweb is wet.

I actually quite enjoy using a manual tuner, there is something quite satisfying about getting the needle on the meter down to zero.

I know what you mean Mark.  

I used to love tweaking those dials carefully not being satisfied until I got that 'perfect' SWR. Something about it that's quite soothing and feels like you're part of the radio experience even slowing your thoughts carefully about that next radio contact. Nowadays a quick crank and click here & there does me fine after performing the former several hundred times.

There is something to be said for the relay flutter of an Auto ATU recalling it's memory settings. (Nice ATU there Mike!) But I do recall as a younger man visiting a Ham friend who grabbed that crank handle of the Roller-coaster inductor on his homebrew ATU whirring it around like crazy. He used to give me a smile and exclaim "Just starting her up! - Chocks away!!"

Thought I had said in a previous post that the idea of using FT8 to tune is rather ingenious, Victor., that will be my preferred method from now on.

More than likely Mark but good information is always worth repeating.  

Plus I can't always remember every one of the almost 5000 postings I've made so bound to repeat myself....that or dementia is starting to kick in!

The FT8 tune method is less invasive on the spectrum available to us, even a quick CW tune in an empty space is almost no bother. (Until someone exclaims that CW is not allowed in the 'voice' allocation....  )

All far, far better than cranking everything up and shouting out "Hola! Hola!" or the elongated "1,2,3,4....1,2,3...1,2,3,4,5.....Fiiiiiive.....Fiiiiiii-va" often encountered on air. (Usually without an identifying call sign too!) 

Definitely superior to 'tuning-up' all over someone's QSO.


I congratulate you Mark on asking others for the 'best procedure' rather than struggling on your own, or heaven forbid performing any of the poor examples mentioned. It all makes for a good Radio Amateur operator.

Victor wrote:

The FT8 tune method is less invasive on the spectrum available to us, even a quick CW tune in an empty space is almost no bother. (Until someone exclaims that CW is not allowed in the 'voice' allocation....  )

All far, far better than cranking everything up and shouting out "Hola! Hola!" or the elongated "1,2,3,4....1,2,3...1,2,3,4,5.....Fiiiiiive.....Fiiiiiii-va" often encountered on air. (Usually without an identifying call sign too!) 

Definitely superior to 'tuning-up' all over someone's QSO.

Seconded! Digital noise and notch filters in some radios and external DSP devices can almost, and sometimes completely, eliminate a single intrusive tone. I haven't seen any that can eliminate a "Hola". Great suggestion.

Victor wrote:

I congratulate you Mark on asking others for the 'best procedure' rather than struggling on your own, or heaven forbid performing any of the poor examples mentioned. It all makes for a good Radio Amateur operator.

I took the time and effort to pass the exam, so I am making the effort to do things properly. A little under 10W out and good operating procedure won't hurt me.

Well said Mark my friend, very well said indeed.