K3 CONFIG LIN OUT
Locked
 
|
Anybody know just what the voltage range can be put out at the line out jack?
Since it is pre-AGC it isn't a "constant level" output but instead varies with signal strength. CONFIG LIN OUT apparently adjusts the level. I want to directly drive a TNC which has an unbalanced 10K ohm input impedance which" can be directly connected to a wide variety of receiver audio output terminals including ... line 600ohms..... The maximum input should not exceed +1.7 V rms.." I suspect the K3's level may be too low at any setting since it is meant for sound card input. My guess is that the TNC would be happy with 0.5 volts. There doesn't appear to be any "constant" level AF output which some rigs had to drive TNC's. K3KO |
|
|
> Anybody know just what the voltage range can be put out at the line out jack?
> > Since it is pre-AGC it isn't a "constant level" output but instead varies > with signal strength. CONFIG LIN OUT apparently adjusts the level. It is in fact post-AGC. CONFIG LIN OUT adjusts the gain of the post-AGC amplifier that drives LINE OUT. Most claims of "constant level" output are actually "fixed gain after AGC", same as the K3. Your specific case of 1.7 V RMS is 4.8V p-p. The driver for the LINE OUT output operates from a 3.3V supply, so it probably will not overdrive your external device in any case. 73, Lyle KK7P (You can measure the output with a multimeter in your particular setup for your particular AGC and other settings.) _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
|
|
Tnx reply.
Don't know why I said pre-AGC. Manual clearly says post AGC. Wasn't worried about too much voltage. Rather concerned about too little-- given that the output is intended for sound card inputs. Was hoping to identify if this were a problem before arrival. Will do the measurements after the K3 arrives. The measurements will be "plug in TNC". Hopefully LIN OUT will have enough range to get to the -3dbV my current line out audio source provides. 73 de K3KO
|
|
|
In reply to this post by KK7P
Had two reports of LINE OUT "level" on this posting.
With LIN OUT at 100: 1) 500 -700 rms mv when tuning across band 2) When attached to sound card, max sound card gain had to be used to get decent signal. Perhaps LINE OUT levels are indeed too low. 73 de Brian/K3KO
|
|
|
Hi Brian:
Not so on my K3. No specific voltage levels available, but with the sound card Line In gain set to 50%, I had to turn down the LINE OUT level to 28 - 30 to keep from overdriving the sound card. There was plenty of volume from the l'il Dell speakers to fill the room with the "Master Volume" sound card control set to 50%. 73, Ken K3IU K3 #202 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ K3KO wrote: > Had two reports of LINE OUT "level" on this posting. > > With LIN OUT at 100: > > 1) 500 -700 rms mv when tuning across band > 2) When attached to sound card, max sound card gain had to be used to get > decent signal. > > Perhaps LINE OUT levels are indeed too low. > > 73 de Brian/K3KO > > > Lyle KK7P wrote: > >>> Anybody know just what the voltage range can be put out at the line out >>> jack? >>> >>> Since it is pre-AGC it isn't a "constant level" output but instead varies >>> with signal strength. CONFIG LIN OUT apparently adjusts the level. >>> >> It is in fact post-AGC. CONFIG LIN OUT adjusts the gain of the post-AGC >> amplifier that drives LINE OUT. >> >> Most claims of "constant level" output are actually "fixed gain after >> AGC", same as the K3. >> >> Your specific case of 1.7 V RMS is 4.8V p-p. The driver for the LINE >> OUT output operates from a 3.3V supply, so it probably will not >> overdrive your external device in any case. >> >> 73, >> >> Lyle KK7P >> >> (You can measure the output with a multimeter in your particular setup >> for your particular AGC and other settings.) >> >> _______________________________________________ >> Elecraft mailing list >> Post to: [hidden email] >> You must be a subscriber to post to the list. >> Subscriber Info (Addr. Change, sub, unsub etc.): >> http://mailman.qth.net/mailman/listinfo/elecraft >> >> Help: http://mailman.qth.net/subscribers.htm >> Elecraft web page: http://www.elecraft.com >> >> >> > > Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
«
Return to Elecraft
|
1 view|%1 views
| Free forum by Nabble | Edit this page |