r-390a diode output

[K5IIA]

ok here is what i would like to do.. I would like to make recordings of people off the diode output of my r-390a to the computer.  what is the output of the diode output as far as impedance i guess.  depending on the answer to that what would be the best way to connect it to either the line or mic input of my pc? 

i will just leave it at that and see if this is an ok way to even try to do what i want to do.

right now i just have a full range speaker on the speaker output of the 390a.  future plan is to do a hi-fi tube audio amp on diode output to a nice speaker system but i figured i would run the first idea by and see if it something i could make work this weekend.  if the pc to diode output is not a good idea, any other ideas are welcome.

73
brandon
k5iia lewie see anna

[K1JJ]

Hola, Brandon -

Congrats on dropping the 'F' from your old call, OM.  

Here's some info on hooking up the diode detector for a stereo amp system. This is a good way to go.   I like using the big audio amp and big wall speakers best for hi-fi audio.

http://amfone.net/ECSound/K1JJ4.htm


Some of these general testing principles apply not only to transmitters but to receiver audio as well:

http://www.amfone.net/ECSound/K1JJ5.htm
http://www.amfone.net/ECSound/K1JJ2.htm


The computer input would be similar.  The idea is to get a good signal without hum. Sweep the RX to be sure it's clean, wide and flat.

How's the SoftRock working out?

T

Update:  Steve posted some great info specific to the R-390 below:

[K5IIA]

the softrock works but i'm not sure if it works as it should. if i am rx'ing on 3.885 and a huge signal is on 3.880 i do not see a big carrier sitting there next to 3.885.  i got it working and need to mess with it some and just havn't.  if i dont do anything with the softrock in a few weeks i may look to pass it on. just have tosee.

ok well i'll check out the links.  and do me some reading.

[Steve - K4HX]

From Chuck Rippel's The R-390 Owner's Manual:

Speaking of audio, supurb results can be realized by coupling the "DIODE LOAD" point on TB-103 located on the rear of the receiver to a Hi-FI amplifier. Simply obtain an audio extension cable with an RCA plug on one end from Radio Shack. Place a 470K resistor in series with a 10uf, non-polarized (also available at Radio Shack) capacitor and connect it to one of the screws holding the jumper across the "DIODE LOAD" screws on TB-103. Do not remove the jumper. Connect the other end of the capacitor/resistor network to the center conductor of the RCA cable then ground its shield to the "GND" screw located on TB-103 immediately to the right of the "DIODE LOAD" screws. Plug your cable into the TAPE or AUX jack on your stereo receiver, adjust the tone controls as appropiate and enjoy.

More at the link.

http://www.amwindow.org/tech/htm/r390man.htm

[Ed/KB1HYS]

Not quite the same, but I took an old RCA BC parts rig and fed the 455khz IF from my R-390A to it's detector directly.  Basically the R-390A's front end with a BC audio output.  I thought it worked pretty good.

[K1JJ]

the softrock works but i'm not sure if it works as it should. if i am rx'ing on 3.885 and a huge signal is on 3.880 i do not see a big carrier sitting there next to 3.885.  i got it working and need to mess with it some and just havn't.  if i dont do anything with the softrock in a few weeks i may look to pass it on. just have tosee.

ok well i'll check out the links.  and do me some reading.

Brandon,

The SoftRock - maybe the crystal needs to be moved/changed to slide that image down the band. Does the sync detector and pan adapter work OK?   Bud, what do you think?  

It's well worthwhile to get it running right with the R-390 - for the  sync detector, sharp filters and spectrum display. You will hear better. Don't give up on it yet.

T

[KA8WTK]

Remember to have the R-390A filters set to 16kc. The Softrock will only "see" what makes it through the filters. Do your filtering in the SDR software.

Bill