[CQ-Contest] Busted Reversed Beacon Network spots

Pete Smith N4ZR n4zr at contesting.com
Sun Jun 9 10:04:21 EDT 2013

Interesting - I "admitted" what?  That there are a lot of Softrock-type 
receivers on the RBN, some of which have inadequate I/Q image 
reduction?  Sure. That direct downconversion receivers like the QS1R 
occasionally throw what look like I/Q spots, even though there is no 
simple explanation.  Sure.  I saw mine throw one of those just 
yesterday. Wish I knew why.

The RBN teamis actively working on a promising technological solution to 
get rid of all of thisclass of busted spots.

Wrong-band spots are quite another creature.  I'm still waiting for data 
on these, but think that either inadequate harmonic suppression and/or 
intermod will be shown to be the source. If that's the case, then the 
receiver used probably makes little difference.

Bret, before you attack SDR receiver performance indiscriminately, take 
a look at Rob Sherwood's review of the KX3.

73, Pete N4ZR
Check out the Reverse Beacon Network at
blog at reversebeacon.blogspot.com.
For spots, please go to your favorite
ARC V6 or VE7CC DX cluster node.

On 6/8/2013 11:37 PM, Brett Graham wrote:
> Eventual admission from N4ZR that a subset of just 
> wrong-freq-same-band spots were seen at a tad over one-per-minute 
> (during a contest) got me looking at this again, using non-weekend RBN 
> data for 2013-03-08 (also with all spots of DXpedition/special event 
> calls omitted, so hopefully missing majority of stations deliberately 
> QRV on >1 band or >1 frequency within same band simultaneously, or 
> deliberately transmitting a fecal signal as no contest that day). 

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