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
there is only one SMD element antenna in use. To me it looks like a a resitor(capacitor which is unlikely) and this SMD element is located at the output side of the Balun towards the coax connector. 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