Re: [Discuss-gnuradio] argggg .. WBX Front end issues

[David Kierzkowski]

thanks Marcus. Some of the signals i am monitoring are very
address@hidden 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.
>