Rf attenuator / SCU Gain

Wayne

The manual for the 6400M indicates the front end RF preamp/attenuator can be set between **** and ****. On the menu there is a slider and apparently it is band independent. However there is no scale to indicate what it is set at other then all the way to the left is minimum and all the way to the right is maximum.

Is there anymore info than that as far as the value of db that is inserted as attenuation or gain that the slider matches up with?

Jim K4JAF

If you look at the screen on the top right as you move the slider, you will see a value which changes from -8db, 0 (nothing on screen), 8db, 16db, 24db, 32db

Wayne

Got it thanks revisited the manual and there it was in black and white.

KB4OIF

What page Wayne.  I have a neighbor that is about 200 feet from me that is on the same band as I am.

KB4OIF

OK.  i have a neighbor who's antenna is about 150 feet from mine.  I have not been able to find any type of attenuator to attenuate his signal.  at times we are on the same band. I am on 7.222 and he is on 7.251.  I read the info on page 162.  Can someone point in the right direction.

Bill -VA3WTB

Maybe make sure you receive filters are set to steep.

KB4OIF

What page in the manual that discusses this.  i.e. receive filters  Is it in equalization in the audio tab??

Bill -VA3WTB

I don't have one of the new radios, I have a 6500 SSDR for windows. Under radio setup/filters

Wayne

The 6400M manual states it can be adjusted from -8db thru +32db in 8 db steps. Therefore the bar from left to right per position or click is: -8 / 0 / +8 / +16 / + 32 /  Any position choosen which is NOT Off (0db) results in the setting such as -8db to be shown in the upper right corner of the Panadapter.

However since there is only 1 SCU on the 6400M you cannot have a different setting of the Preamp per Panadapter the preamp function applies to the SCU however is displayed on the Panadapter'

Reference Page 84 of the 6400M/6600M User Guide Version 2.1.30 published 1/29/18.

Tim - W4TME

The problem is that your neighbor is physically too close and depending on the frequency, your antennas may be in the near field of each other.  The attenuator in the radio is not designed to address this type of issue.  External filters with much greater attenuation will be necessary.  And if you are on the same band, any attenuation will inhibit your ability to receive weaker signals.  Your only choice, if he is on the air, is that you are on a different band.  And possibly one that is not harmonically related to the one he is operating on.

KB4OIF

Thanks Tim.  that's what I thought.  He is net controller on one and I am a net controller on another one.  His is in the AM and mine is PM.  I normally just check out when i see his signal up the band.  I have no problems with that.