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6300 attenuator lack questions

IW7DMH, EnzoIW7DMH, Enzo Member ✭✭
edited June 23 in SmartSDR for Windows

during these summer nights I had more time to do some listening on low bands, mostly on 40 and 80 meters. In a A/B comparison with another Stars and Stripes rig I realized that the use of attenuator could help a lot in the "noise handling battle".
So I am wondering if, in next SSDR releases, 2.0 or higher, also a 6300 rig can have a 10 db attenuator or if are there any technical issues that justify this feature lack.
I have a work-around for this: usually I reduce the AGC- threshold and add AF gain but I don't know if it could be better with a fixed attenuated signal.
Could 6500 and 6700 owners tell about their experience?

Thank you very much and 73

Completed · Last Updated


  • Rob BlackieRob Blackie Member
    edited July 2016
    I agree, a straight forward attenuator would be handy, the suggested AGC works to  a point but yes you are right :)
  • edited December 2016
    Enzo, Have you tried to move the RF Gain slider control to the far left position?  Go to the ANT option on the far left side of SSDR and click at the "0" position for a Minus 10 Db gain in the RF level.  This works well on my 6700 station.

    Les - K6ZF
  • Ken - NM9PKen - NM9P Member ✭✭
    edited June 23
    I have a 6500 and seldom need any attenuation on 160-40 meters. I do use 10 dB gain above 20 meters and 20 dB at 6 meters. All the attenuation would do is lower the noise floor and prevent overloading the receiver, which NEVER happens at my station. Setting the AGC-T has the same effect for me. I thought, however, that the 6300 did have attenuation, as Les K6ZF described. I know that currently the 6300 preamp is actually gain-contoured so that at lower frequencies it doesn't actually provide any gain. (In order to protect the 6300 front end.)
  • KM6CQ - DanKM6CQ - Dan Member ✭✭
    edited June 2019
    At my location with a full wave loop, on my 6500 I use 10 db attenuation below 20 meters at night. I adjust the AGC-T so the noise floor does not trigger it. This makes for much less listening fatigue because, it keeps the band noise to a minimum between dits and dahs and words.  
    I would prefer a 3 step attenuator in 6db increments.

    73,   Dan KM6CQ
  • HCampbell  WB4IVFHCampbell WB4IVF Member ✭✭
    edited December 2016

    You could use an external step attenuator (MFJ-762, etc.) along with an antenna interface (such as the DXE RTR-1A).  The RTR-1A has other uses, such as letting you add a receive antenna to the 6300. 

  • IW7DMH, EnzoIW7DMH, Enzo Member ✭✭
    edited January 2017
    Thank you very much for your feedback.
    I found that 0 db antenna gain is not enough, here in Europe, for 40 and 80 meters. That was the reason I asked for a -10 o -20 db attenuator.
    Actually I don't like very much the idea of an external step attenuator, I would prefer a software extension of 6300 firmware. I could pay for this enhancement and that is the reason I asked for it in SSDR 2.0 or later version.
    I hope Flex designers will provide a "pay-for-feature" in their next software.

    73' Enzo
  • Rob FisselRob Fissel Member
    edited July 2016
    FWIW, the transverter port on the 6300 makes a fine RX antenna port, which I use with my RF PRO-1B loop. I use the same keying relay as the amp, daisy chained together, to switch the preamplifier off during TX. 
  • EA4GLIEA4GLI Salvador Member ✭✭
    edited November 2016
    Hi Enzo, I thought that on the 6300 the slider to the right on the ANT Gain actually is an ATTENUATOR on 40, 60, 75, 80 and 160m. Let me see if I find a reference on the manual....
  • EA4GLIEA4GLI Salvador Member ✭✭
    edited November 2016
    Here we go, on the Manual for Ver 1.6.21 is on pag. 96.


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