[hpsdr] ANAN 10 28Mhz tx spectrum and generated birdie

Fri Aug 5 13:03:44 PDT 2016

I've seen a not dissimilar spur from another (non-HPSDR) radio. In that
case, it was a contest station at a distance of ~200 miles.

+/-196 *n KHz sounds a bit like a Nyquist image of some sort, assuming
that 196 KHz is the TX sampling rate.

73 de Glenn WB6W

On 8/5/2016 12:24 PM, John Ackermann N8UR wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> Are you sure that you're not overloading the spectrum analyzer input
> and generating distortion in the front end?  One way to tell is to
> increase the input attenuation -- if you add 10dB and the spurs drop
> by more than 10dB, that's a sign of front end overload.
>
> I always try to keep input levels below 0dBm to minimize this problem
> (of course, the overload level is different for every analyzer model).
>
> 73,
> John
> ----
>
> On 8/5/2016 3:13 PM, Dominique Dehays wrote:
>> ***** High Performance Software Defined Radio Discussion List *****
>>
>>
>>
>> So I have done more measurements. Most products are below -80dBc and can
>> be considered as marginal , but there are still  two pairs of products
>> that are in band and -60 and -63dbc. Among theses products there is a
>> pair which reduces when power is reduced , I wonder why as it is not
>> harmonics, maybe intermodulation between carrier and spuriis? I'm not
>> very confortable in generating these products. I'll try the transverter
>> output tomorrow to know what is going on.
>>
>>
>> Le 05/08/2016 à 19:24, Dominique DEHAYS a écrit :
>>> ***** High Performance Software Defined Radio Discussion List *****
>>>
>>>
>>>
>>> Hi dave ,
>>>
>>> so there is something stange on mine. I have just tried to lsn on a
>>> second 28Mhz RX taking care that it is not saturated. I TX on 28.1 and
>>> looking up the band I've found:+196/+251/+276/+451/+786/+1049/+1600Khz
>>> , and I suppose the same down the band below 28.1. I have not measured
>>> the relative levels yet , for sure the two I've written about in my
>>> previous message were -60 and -63 , I'll tell abt the others
>>> later.This is on the 10W output , but trying to reduce power changes
>>> nothing on the spuriois levels I've measured yesterday
>>>
>>> 73
>>>
>>> Dom
>>>
>>>     > Message du 05/08/16 18:45
>>>     > De : "Dave" <g4fre at g4fre.com>
>>>     > A : "'Dominique Dehays'" <f6dro at wanadoo.fr>,
>>>     hpsdr at lists.openhpsdr.org
>>>     > Copie à :
>>>     > Objet : RE: [hpsdr] ANAN 10 28Mhz tx spectrum and generated
>>> birdie
>>>     >
>>>     > Hi Dom
>>>     >
>>>     > I saw nothing within -70dBC inband on my ANAN10 when using the
>>>     xverter port
>>>     > on 28MHz . My Anan has been used on many 2/4m contests with a
>>>     Transverter
>>>     > without complaints from my (VERY) locals
>>>     >
>>>     > This port does however have bad harmonics see
>>>     >
>>>    
>>> http://g4fre.blogspot.co.uk/2013/11/anan-10-as-transverter-driver.html
>>>
>>>     >
>>>     > Dave
>>>     > G4FRE
>>>     >
>>>     > -----Original Message-----
>>>     > From: Hpsdr [mailto:hpsdr-bounces at lists.openhpsdr.org] On
>>> Behalf Of
>>>     > Dominique Dehays
>>>     > Sent: 05 August 2016 17:31
>>>     > To: hpsdr at lists.openhpsdr.org
>>>     > Subject: [hpsdr] ANAN 10 28Mhz tx spectrum and generated birdie
>>>     >
>>>     > ***** High Performance Software Defined Radio Discussion List
>>> *****
>>>     >
>>>     >
>>>     >
>>>     > Hello ,
>>>     >
>>>     > after getting a local friend complaining about hearing me on
>>>     several
>>>     > frequencies , I've measured the anan 10 output spectrum , and was
>>>     > surprised to find spuriis 295 and 590 Khz each side of the
>>>     carrier at
>>>     > -60db/-63dB. I know it is within FCC norms but it is really
>>>     annoying.
>>>     > Another problem is that the anan generates a wide drifting
>>>     birdie in my
>>>     > 144Mhz receiver ( of course a separate receiver not the anan).
>>>     Anyone
>>>     > got the same problems?
>>>     >
>>>     > 73
>>>     > Dom
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>>
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-- 
"i" before "e" except after "c", 
Or when sounded as "a" as in neighbor and weigh.
Or when it's nutricious as "protein"
Unless it's just plain old "weird" 