[hpsdr] ANAN-100D TX Spectrum

[Bill Diaz]

Jacques,
     I do not have access to a spectrum analyzer, but have done some 
limited testing using the ANAN-100D second receiver.

     I have calibrated my PA output on the Setup. PA Settings page to 
ensure I have 100 watts output into a dummy load on all bands as 
indicated by PowerSDR and an external meter.

     I have the "Dup" button activated to show my transmitted signal on 
the RX1 Panadapter.  I also have "ATT on TX" activated with 31 db of 
attenuation.

     When I transmit on 6 meters the RX1 panadapter shows what appear to 
be numerous spurious signals, but RX2 does not show these same signals.

      Upon close inspection, the transmitter shows +11.5dbm signal level 
in the RX1 panadapter.  Of course, this is actually being attenuated 
another 31 db, so the ADC should actually be seeing around -20dbm.  This 
may be approaching ADC overload and the ADC may also be affected by 
stray RF from the transmitter etc.  The maximum RX1 spurious response 
shown is around -65dbm or about 76.5db below the carrier.

      At the same time, RX2 shows a signal level 0f -9dbm, and no sign 
of any spurious signals.  Note that the RX2 antenna relay is shorted to 
ground during transmit.    If the transmitter was actually generating 
spurious signals, I would still expect them to appear on RX2 as well.

     Of course, the foregoing measurements are not exacting, but should 
provide a rough indication of transmitter performance.    I would be 
interested to hear from others who have performed measurements similar 
to yours, as well.

     Bill KC9XG

On 5/12/2013 5:51 PM, f6bki at orange.fr wrote:
***** High Performance Software Defined Radio Discussion List *****

Hello all , today I have  checked the RF Spectrum on transmit of my new 
ANAN-100D.
On 6m there are plenty of spurious about 50 dB below the carrier from 
50MHz down to few MHz .
The ratio Spurious/Carrier  is almost independant of the power level, in 
comparaison an IC7000 is at least 20 dB better around the carrier and 
much better away from the carrier. .
On the other bands the spurious are about -60 dB below the carrier .
Looks very high !!!! No way to drive an amplifier with such a signal!!!
Mesurements have been made on a 50 Ohms load on an  ADVANTEST Analyseur .

As anybody checked his ANAN-100D ??

73
Jacques F6BKI

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