Setting up RF Pre-Amp Antenna Gain Properly on the Flexradio 6XXX

-


Copied from this flexradio helpdesk forum for reference.

https://helpdesk.flexradio.com/hc/en-us/articles/204923669-How-to-determine-the-amount-of-RF-Preamp-gain-to-apply-for-band-conditions

As a rule of thumb, you want your antenna noise to show an increase in your S-meter by 8-10 dB and no more. If the noise goes up more than 10 dB with the RF preamp and antenna, you have too much RF gain and the SNR is degraded.

  1. Find a clear frequency on your VFO.
  2. Set the slice receiver mode to CW and the receiver passband filter to 500 Hz. Turn off any noise reduction, APF, RX EQ that will add gain to the receive audio.
  3. Disconnect the antenna - You can select an antenna input with no antenna on it like RXA or XVTA.
  4. Note the dBm reading with no antenna connected.
  5. Connect the antenna.
  6. Note the reading in dBm. This is where an accurate dBm calibrated S meter really counts. Ours is truly 6 dB per S unit and measures the actual receiver sensitivity in the selected bandwidth.
  7. If the noise goes up about 8-10 dB, you have the optimal RF preamp setting for the noise on your antenna for the given time of day and propagation.
  8. If the noise with the antenna connected goes up significantly more than 10 dB, you have too much preamp gain, which will limit dynamic range for large signals. Reduce preamp gain.
  9. If the noise goes up much less than 8 dB, increase preamp gain to get it closer to the 8-10 dBm increase.

Comments

Post a Comment

Popular posts from this blog

Remote CW with RKI 1.05 and Sparkfun FT231X breakout board

-
Image
I've created a workable solution for sending CW via a "straight key" to my remote Flexradio 6600 at the lake using RemoteKeyerInterface (RKI) and a simple Serial/USB circuit.   RKI is only available for Windows. RKI enables you to use paddles or a straight key to send CW through a remote Flex‑6000 transceiver.  After several iterations I've settled on a design using the Sparkfun FT-231x breakout board and RKI v1.05 that was originally posted by Gary KT7AZ on the RKI  groups.io forum .   However, to send CW reliably via a straight key - there were two main problems I had to solve. First,  I had to resolve the network latency and buffer bloat in my shack's network by setting up a router with Smart Queue Management.   The Ubiquity EdgeRouter  was recommended by a friend of mine (Larry N1FG) and has been working great.  I'm using the 4 port Edgerouter X which was only $50 at microcenter (open box special).  No more audio stutterin...
Read more

BENS BEST BENT WIRE

-
Image
Update 11/19/23 - Tribute for Bill Crane, SK 10/26/23: https://youtu.be/Znyqq9f93r0?si=bxPV0zVmGN7oWo_u ++ Update August 22, 2022.   I was able to find Bill Crane W9ZN on the air by looking for his spots on RBN .   Took me a while to see the pattern on when and where he's be on frequency, but not only did we make the QSO, we exchanged cards as well!  This is one of my favorite QSL cards that I've collected so far.  Thank You Bill!     73 Chris de WX7V ==================================== Last month I asked a members of the Straight Key Century Club  what was their favorite way to warm up before sending morse code.  I got a lot of input - from, "Just jump right in" to sending the Alphabet and the Numbers 0-9.   My favorite answer is to practice sending Bens Best Bent Wire, with the letters and numbers run together so that the code produced sounds similar to a march.  Apparently this was taught by the RAF,  merchan...
Read more

FTdx3000 - configuring external panadapter using SDRPlay RSP1A

-
Image
 The panadapter on the FTdx3000 is fine but not great.   I'm using SDRuno with the SDRPlay RSP1A  which is a significant upgrade!   Cost was minimal since I already had a RSP1a stored in a  drawer waiting for a problem to solve.   Hardware configuration is straight forward.  On the back of the FTdx3000, connect the IF OUT (RCA connector) to antenna input on the RSP1a.  I needed a cable with RCA to SMA adapter.  Plug in USB connections from the RSP1a to the computer, and another from the FTdx3000 radio to your computer. Download and install OmniRig from dxatlas.  Omnirig provides CAT control for the Yaesu radio - allowing you to automatically tune into any frequency by clicking signal in panadapter waterfall.   Find the SiliconLabs Enhanced Comm port (use Ports in Device Manager)- you need to use the same com port and speed settings in the omnirig and sdruno configurations. Start sdruno, click on settings - the...
Read more