Re: FT8 checking my signal


On the 3rd model move the left hand diode over in parallel with the right hand diode.

And with Schottky diode pair the limiting voltage is in the approximate range of 0.3V not 0.7v. This may introduce distortion in bad cases.


On 20210405 23:51:01, Bill Walch wrote:

The original photo shows two Schlocky Diodes (1N5817) in opposite polarities, forming a bi-directional clamp. This is illustrated in the diagram (c) below. The major difference between a typical signal diode (rectifier) is that a Schlocky Diode is extremely fast switching, in the order of uS. You can see datasheet for the 1N5817/8/9 HERE. This diode is rated at 10A maximum Forward rms current. How that relates to induced RF, is unknown to me. However, I would assume that if the Tx and Rx antennas are separated at some distance, the amount of RF energy seen at this clamp should be low enough to prevent damage to the diodes, again, speculation on my part. Hope this helps.

73's, Bill

On 4/4/2021 5:57 PM, bammi via wrote:
Circuit and Diode type and model would help me understand how it is working. The picture is not speaking a thousand words unfortunately :-)

73 de k1jbd

Join to automatically receive all group messages.