Insulation RX Transformer

By: Igor Grigorov, va3znw

At my shack I have used a Coaxial Antenna Switch Protax CSR- 5G to change devices switched to my antenna. Figure 1 shows commutation graph and schematic of the switch. Figure 2 shows the switch sitting at my table. The switch is very convenient for amateur operation in the Air. I can easy switch antenna from one transceiver (ICOM- 718) to another one (K1) or turn antenna to general coverage receiver (Hallicrafters S-85). I use the receiver to check propagation in the Air and just to catch some interesting HF- stations.

I have bought the switch at some Hamfest for 5 dollars. It is very reliable switch that worked at me without any problem. Somedays I discovered ads of the switch at old 73- Magazine from 1967. Figure 3 shows old advertising of the switch from 73- Magazine # 1, 1967.

Figure 2 Protax Coaxial Antenna Switch Sitting at my Table

The switch costs $ 12.50 in 1967. I used online calculator (http://www.dollartimes.com/index.htm) to find value of the one dollar from 1967 to dollar in 2015.

It occurred that one dollar from 1967 cost 7.13 dollars from 2015. So the switch would cost 89 dollars if being sold in the 2015 year.

Figure 1 Commutation Graph and Schematic of the Switch

www.antentop.org

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