transmitting close to sdr play

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transmitting close to sdr play

Post by w5ytt » Sun Dec 20, 2015 10:46 pm

is there any easy way to protect the sdrplay when i transmit on the same property and frequency on different antenns
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Re: transmitting close to sdr play

Post by dsalomon » Wed Dec 23, 2015 3:47 pm

There are several things you can do.

Disconnect the coax before each transmit, but that's a lot of trouble.

You can home brew a switch, assuming your transceiver has an amp interface (transceiver amplifier keying line). That same interface can be used to build a circuit that will switch the receive antenna to ground. There are also lots of these types of interfaces available commercially.

Doing a google search on "front end receiver protection" will return a lot of home brew and commercial solutions. Most of the home brew solutions are easy to build and use very few, inexpensive parts. If you prefer to buy a solution, DX Engineering sells this: or this: It's an RF limiter that stays inline full time and limits the signal to a safe level. Looking at their website, I can't really tell the difference between the two units, other than $10 more for the "HD" one. Note that the website says the units cover 150KHz to 150MHz. Array Solutions also sells one: (same frequency coverage).

My suggestion - home brew a switch. It's easy and inexpensive and there are lots of places to find plans / circuits.
Last edited by dsalomon on Thu Jan 01, 1970 12:00 am, edited 0 times in total.
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