ANTENTOP- 01- 2017 # 021

VHF ATU

VHF ATU

Brett Johnson

Credit Line: Facebook group: The Urban Radio Ham.

Now many of you may think WIRE antennas are the preserve of the HF bands. Well not so. I have a "long" wire here that gets used on 2 m - and for this some form of ATU is handy - here is a simple one I made.

It has 2x100-pF Variable Capacitors (because that is what I had at the time) and the coils are 5 turns on a 5 mm former. As you can see basically it is a PI configuration (same as is in the MFJ units - but a fraction of the price).

It can also act as a stand alone antenna base for a 1/4 wave or even 5/8 - but you will need some sort of counterpoise (hence the terminal on side) - and will match/tune (what ever you want to call it) most 2 m antennas and wires. The ATU can stand 50 w through this with no problems as it depends on the Variable Capacitors that are pretty wide spaced. The ATU may solve a problem (with antenna matching) or allow you to use a long wire or even a Rhombic if you have room for it.

Inside View

VHF ATU

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