Sunday, April 16, 2017

40m vertical balcony antenna using PAC-12 , adjustable coil and telescopic whip

Just want to share an updates on balcony antenna using the following setup :-

PAC-12, coil and whip antenna with mounting
PAC-12, coil and 5.6m telescopic whip

Adjustable coil
Equipments :-
Antenna Base : PAC-12
Coil : Adjustable coil ( max inductance is 23uH )
Antenna : 2.5m or 5.6m telescopic whip at 2.29m length
Frequency : 7.080Mhz ( near JT65 freq  )

Telescopic whip ( either 2.5m or 5.6m length) at 7 1/2 feet ( 2.29m ) and the adjustable coil at 21.31uH.

This is the reading of the antenna analyzer at JT65 frequency, complex impedance of  25 + j0, SWR of 1.26:1, therefore I do not need to use any antenna matching tuner. When I transmit at 25W, the meter reads an output power of 20-22W going out to the antenna.

The antenna analyzer is a version of SARK100 called MR100. The details at summary links below.

MR100 showing the SWR
LC100A LC meter to measure the inductance.

LC meter show the coil henry readings

The below is the result of the short 40m balcony antenna, I am able to reach both Europe and USA using it.. In my condo, I am almost surrounded with highrise buildings and not much openings.


Summary Links :-


  1. Hi I am Giovanni the link is very interesting , but
    the adjustbale coil in the chinese link is not possible to understood. Is there a possible english link , how much is the price of the complete set?

    1. You can translate the links into your local language or english (that what I did) ... for taobao is for China market but we usually use a logistic forwarder with a China address to re-pack and send to your destination country ...

  2. "logistic forwarder", is that a "middle man" in your own country or my own country who receives the order from China and then sends it to the customer? Similar to the way Baofeng radios are shipped?


  3. 您直接把PAC12电感以上部分横过来放置了吗?请问是否做了地线或者地网?

    de bg6lh