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

[John Ackermann N8UR]

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:
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>
>
> 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 :
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>>
>>
>> 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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