Antenna tuner

[Boogieman]

My rig is a Kenwood TS430s with the stock hand microphone.

I came across a MFJ 901 antenna tuner.

After setting the tuner for a particular frequency, do I need to retune it every time or leave it there and keep notes of the antenna freqs?

I am taking the Tech test next weekend.

Your help is appreciated.

 

[TonyV225]

you will have to retune when changing frequencies but if its within the same band it will be just simple slight adjustments or touchup. Its pretty simple as far as that goes as you will find out as you experiment or start playing.

When changing bands its a bit mor critical and theres a bit more tuning involved. The best thing to do is to just get a fresh notebook dedicated to that tuner and radios settings and use it for recording the frequencies and transmitter and antenna setting along with inductance settings if the antenna tuner sports the roller inductor.

This just helps when going to a frequency you use often or occasionally visit. Ihope this helps and I answered your question if not Im sorry and I can try again. Good Luck on the testy Im sure you will do fine .....Tony

 

[W5LZ]

Boogieman,
I would think it depends on how you operate, the amount of frequency changing you do, and how much change when you do change frequencies. If you 'hang around' particular frequencies, then I'd certainly note or remember the tuner settings for those. Not really a bad idea to note the settings for any/all frequencies you use, sort of, but that can get sort of a big notebook. I think you'll find that the MFJ-901 has a certain ability to move some distance in frequency before really needing to be re-tuned. I have no idea how much that would be, and it would be different for each antenna used. Once you get an idea of how much tuning range the tuner has, you will be able to make a guess about when to twiddle the knobs on that tuner again.
The first time or two will be the hardest, as far as tuning goes. Mainly cuz you don't know where to set things to start with. After going through the tuning process on each band of use, you at least know where to set the knobs to start with, and then it's just a matter of 'fine' tuning for where ever you stop.
The only warning I would suggest in your situation is that the rating for that '901 is very close to the '430's abilities (power). Most commercially made tuners give their power ratings in Pep, not average. So, cutting that rating in half is a very good idea when determining if a tuner is large enough for whatever power which is normally used. The '901's max rating is real close to a typical '430's power rating. I'd sort of build up to that, and pay particular attention to sudden changes and/or noises from the tuner. That doesn't mean you can't use that tuner, just be careful about it.
- 'Doc

 

[Beetle]

You can keep track with a notebook, like Tony suggested, OR you can get some sticky labels and just put them on the front panel indicating where to turn which knob for which band. For roller counters, something like "14 = 10M" will help speed things.

Remember that your "tuner" doesn't do anything at all to the antenna proper. It adjusts the impedance your radio "sees". If the SWR measured at the antenna's feedpoint is 3:1, you'll still have a 3:1 SWR on the feedline, along with the additional losses that condition brings.