Re: LED brightness


Robert, VA3ROM
 
Edited

Hi Les,

I had the same problem and talked to Chris about the wording in the documentation and he had me do some voltage measurements which turned out to be normal.. The red LED should indeed glow at about the same brightness as the green LED. If you induced a deliberate short (as I did for testing) the red LED will go "nuclear" and it will noticeable increased in brightness very, very noticeable. Chris just has to change the wording of the documentation about the red LED. I bought CCW antenna because it can feed two separate receivers and it has a high immunity to nearby transmitting antennas and protect the receivers (150 watt key down for up to 30 seconds). I just can't tell you how many low-end receivers I've blown up because they don't have much in the way of front end protection.

BTW doing my voltage tests I found that because of the antenna design there was about 8 VDC on the upper dipole where it connects to two back to back diodes so Chris suggested that I change the short wire connecting it to the diodes to a 100 nF (104) 50 VDC capacitor but keep the two ferrite beads and put them on each leg of the capacitor. I don't know if Chris is going to use this modification in later versions or make annotations to the documentation or not. I don't think it's a big deal but I didn't feel comfortable with a receive antenna having any kind of DC voltage on an antenna element. But that's just me! I should have taken a picture of capacitor mod before I put it into operation, but I think that Chris is going to add it for later productions and perhaps add a picture and instructions to the docs for those who'd like to do a retrofit for their antennas. It probably doesn't make any difference reception wise, and it may not even be an electronic or safety issue, but since the bottom element has a 100 nF cap why not do the same for the upper element, eh? ;)

Anyone can access my KiwiSDR from the SDR.hu ("VA3ROM") along with about 400+ others 24/7 and my SuperSID VLF graphs (and others) fromĀ http://sid.stanford.edu/database-browser/. My Kiwi is programmed to provide 8 receiver channels, but I've limited access to one receiver channel per IP address but I don't limit the user time per session.The RDF (TDoA) capability is a lot of fun to use with multiple Kiwi's

I also use CCW's five-port antenna coupler to feed 5 receivers from one HF antenna system, (just an excellent product and tool for Amateur Radio science projects) so I now can feed 7 receivers at the same time (5 on one antenna and 2 on another).

Edit to add: One port of the CCW's power bias-T box feeds my KiwiSDR (10 kHz to 30 MHz) and the other feeds my SuperSID VLF receiver (0 to 30 kHz). Both are showing the same signal strength reception on the VLF beacons between 20-30 kHz.
73,
Robert, VA3ROM
http://www.va3rom.com

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