Pretty sure the ESD diode on that balun is a proper protection diode, BUT an antenna input protection diode isn't going to do much if the system isn't grounded properly on the antenna input side.snn47 wrote: ↑Sun Dec 30, 2018 9:42 amRCND and all
It is interesting to note that the NooEelec 1:9 Balun claims to be with Antenna Input Protection, which if true should have protected your dongle. Does anyone have a scrematic or type list of the protection components used? From the picture on amazon I asume that they just used a resistor.
Sufficiently high static electricity takes only a few nano seconds of peak voltage to damage the semiconducters in a receiver.
From experience even prior to the first lightning bolts, sparks were continiously between the inner conductor of RG-213 coax cable several centimeter to the stone bottom below the roof. The antenna was just a small 10 m 1/4 wave groundplane, much shorter than what a long wire will pick up.
RTL-SDR V3 long wire problems (SOLVED)
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Re: long wire problems
Re: RTL-SDR V3 long wire problems (SOLVED)
Looking at the picture from the NooElec Balun One Nine - Tiny Low-Cost 1:9pretty sure the ESD diode on that balun is a proper protection diode, BUT an antenna input protection diode isn't going to do much if the system isn't

For a long wire antenna which is asymetrical a 1:9 UnUn (Unbalanced/Unbalanced) would be the correct use unless two longwires of indentical length would form a symetrical antenna for which a 1:9 (Balanced/Unbalanced) is used.
Has anyone read which frequency range the 1:9 BalUn is rated for?
Re: RTL-SDR V3 long wire problems (SOLVED)
Hello All:
The SMD is a ESD protection device. It is a varistor on the 50 Ohm side of the Balun.
The SDR must have a ground for this device to protect it.
There is no ESD drain resistor on the antenna side as shown in their schematic.
For a long wire antenna, there is a trace on the bottom of the balun that is cut. Then one post is for the antenna, the other for ground.
A 1 Meg Ohm resistor should be installed between antenna and ground as a static drain.
Robert
The SMD is a ESD protection device. It is a varistor on the 50 Ohm side of the Balun.
The SDR must have a ground for this device to protect it.
There is no ESD drain resistor on the antenna side as shown in their schematic.
For a long wire antenna, there is a trace on the bottom of the balun that is cut. Then one post is for the antenna, the other for ground.
A 1 Meg Ohm resistor should be installed between antenna and ground as a static drain.
Robert