[time-nuts] GPS simulator,

Bob Camp lists at rtty.us
Thu Nov 25 20:15:20 UTC 2010


Hi

It's not real clear that they do anything more than sample the RX and play it back for the TX. 

Bob

Sent from my iPhone

On Nov 25, 2010, at 9:39 AM, "J. Forster" <jfor at quik.com> wrote:

> Agreed. The trick is to properly partition what is done in hardware ane
> what is done in software. This could eliminate a lot of logic hardware.
> 
> Clearly, the RF stuff and modulator are hardware.
> Ditto PR code generation.
> Everything else in SW, I think.
> 
> FWIW,
> 
> -John
> 
> ===============
> 
> 
>> Hi
>> 
>> One bit serial at 16 MHz isn't all that fancy any more. Sounds like a
>> shift register feeding a couple filters.
>> 
>> The money must be in the receive side.
>> 
>> Bob
>> 
>> On Nov 24, 2010, at 5:14 PM, ernieperes at aol.com wrote:
>> 
>>> 
>>> 
>>> 
>>> Hi,
>>> 
>>>  found an interesting unit. I think it is not for the usual pocket
>>> money for a time-nuts.
>>>  have a look...
>>> 
>>>      http://www.chronos.co.uk/pdfs/rac/labsat.pdf
>>> 
>>> Rgds Ernie.
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> -----Original Message-----
>>> From: John Green <wpxs472 at gmail.com>
>>> To: time-nuts at febo.com
>>> Sent: Mon, Nov 22, 2010 6:43 pm
>>> Subject: [time-nuts] GPS jamming susceptibility
>>> 
>>> 
>>> Given that this is an extremely sensitive topic and completely illegal
>>> lso, let me just state at the outset that I have no interest in
>>> amming anyone's GPS. A while back, I was looking at one of those
>>> hinese discount electronics websites, I'm sure we all have, and
>>> oticed a GPS jammer for sale. I had been wanting to do some jamming
>>> usceptibility testing for quite some time but had never got around to
>>> uilding a generator to test with. The thing was cheap so I ordered
>>> t. After it arrived, I opened it up, first thing, to see how it was
>>> ade. It has a dual 555 oscillator, a couple of analog switches, a 1.9
>>> Hz VCO, a single amplifier. It doesn't look capable of putting out
>>> ore than 50 milliwatts or so into a 2 inch antenna. I was somewhat
>>> ubious that it would do anything, so I took it to the bench where the
>>> 3801 lives and turned it on. Within 2 seconds, the holdover LED lit.
>>> immediately turned it off and within a few more seconds, the
>>> oldover LED was back off. The GPS antenna is perhaps 35 feet away
>>> ith a cinder block wall, a brick wall, and a metal roof in between. I
>>> lso put a 15 Db attenuator between it and the antenna with almost the
>>> ame result. I am going to do more testing with it wired into the GPS
>>> ownfeed an an adjustable attenuator in line just to see how much
>>> ignal it takes. That way, there will be little danger of messing with
>>> nyone's reception. It is just a simple sweeper so it must do its job
>>> y brute force. I am amazed that it took so little to shut my Z3801
>>> own. Has anyone here had any actual experience testing GPS receivers
>>> or susceptibility?
>>> _______________________________________________
>>> ime-nuts mailing list -- time-nuts at febo.com
>>> o unsubscribe, go to
>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> nd follow the instructions there.
>>> 
>>> 
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at febo.com
>>> To unsubscribe, go to
>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>> 
>> 
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>> 
>> 
> 
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.



More information about the time-nuts mailing list