thanks Marcus. Some of the signals i am monitoring are very strong-@860mhz approx 1/2 mile from my receive antenna. I would say from memory they were -30 or maybe -20dbm? Is this to much? My gut tells me no. Is it possible to cause damage by simply turning up the gain to high on a strong signal? I am going to remove all the WiFi stuff from the mast with my antennas. Is all i have to do is solder a new LNA to the WBXFE daughtcard? part numbers? Im with you on the sure arrestors. I do have a polyphasers impulse suppressors in line with all the feed lines coming in for lightning protection but that's a whole different issues.
On 4/12/2012 8:19 PM, Marcus D. Leech wrote: > On 04/12/2012 08:11 PM, dave k wrote: >> blew my second WBF front end after 1 day of wonderfull RX. I don't >> know how it happend. I was using a few different types vhf and uhf >> omnis and yagi antennas, everything seemed to be working fine. Now it >> can't hear hardly anything and the typical strong noise signal in the >> center freq is back. Is it possible that some of the equipment mounted >> on the antenna mast could be shorting it out? Or is the WBX just so >> sensitive that a strong signal can blow it up? I have 2 Ubiquiti >> bulllet2HP's on the roof. One is clamped to the same mast as the UHF >> omni that was connected the to WBX. They are 24V DC over the unused >> pairs. Im really bummed out. Any recommendations or similar experiences ? >> >> _______________________________________________ > Unfortunately, LNAs are notoriously sensitive little princesses. The > new revs of the WBX have TVS diodes between the RF connector and the LNA, > which should reduce this problem, at the expense of a slightly poorer > noise figure. If the local field strength of RF on your roof is high, > enough > can couple in to damage the LNA. In those situations a limiter might > be needed, or even a stiff bandpass filter to keep stray RF fields that > are out-of-band with respect to your application out of the front-end. > > > There's a company online, summitsource, that sells in-line gas-discharge > surge arrestors for CATV/SATV use that I've used for protecting > LNAs in the past. Taken local lightning hits and survived, for what > it's worth. The arrestors are cheap--under $4.00 apiece as I recall, and > have 75-ohm connectors. About 0.3dB insertion loss. > _______________________________________________ Discuss-gnuradio mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
