6300: Two Audio Channels or One

Jim KJ3P

I’m looking forward to a new 6300 being delivered this week (thanks to Flex for shipping exactly on schedule as promised!), and I'm busy making up cables for it.

Audio Out (pwrd spkr jack): I’d like to use a mono powered speaker (my fave Fostex 6301B), by sliding the outputs of the two slices to Left only, and wiring Left to the speaker/amp.

I’m wondering if there’s any reason for staying with a two-channel output scheme. Other than keeping one slice in Left, and the 2nd slice in Right, are there other solid reasons to go “stereo”? Occasionally, if using headphones, I could just center the slice of interest.

   --jim KJ3P

Tim - W4TME

You will not be able to pan the audio between slices when working split or monitoring two different bands or sub-bands.

Jim KJ3P

So, in the examples you mentioned, if both slices are panned full Left, they'd both come out of the Left output simultaneously (mixed together), correct?

Steve N4LQ

Bite the bullet and do it right the first time. If you start shorting speaker outputs together or leaving one un-terminated you may end up with a blown audio amplifier. Go get another Fostex and make it stereo.

Jim KJ3P

My, aren’t we the Negative Nelly.

Ain’t talkin’ ‘bout shortin’ nothin' together. Ain’t bitin’ no bullet.  Ain’t cheapin’ out.  Got four Fostex.

Talkin’ ‘bout any really good reasons to run two separate speakers/amps.  Other than the reasons Tim already mentioned, any come to mind?

Tim - W4TME

Yes, that is correct.

Steve N4LQ

The voltage across an un-terminated amplifier can be excessive. You might accidentally side your balance control the wrong direction.  That's what comes to mind. If nothing else, put a 600 ohm resistor across your dead channel if you insists on not using it. 

Jim KJ3P

Understood.  But the "Powered Speaker" jack (and the line outs in the 15-pin D) are standard consumer IHF (-10 dBV?) outputs, and usually don't want to see a load less than 10K ohms (this depends greatly on the circuit design), which is what I just finished soldering up. Signal voltage at these outputs seldom reach 0.5 Vp-p, but I still wouldn't put them through a resistive combiner without access to the schematic. But as Tim has confirmed, the pan controls in SSDR will do what I need.

Ken - NM9P

Perhaps a reiteration of Tim's comments, but I have found it very handy to have the full stereo output, both in my speakers and the headphones for the following purposes:

1) Working split . . . the DX station in both ears, and the "mob" in my right ear.  It makes is very easy to monitor the pileup activity at low and off-center volume but have both ears tuned to the weak DX station.

2) Just the opposite when I was running as W1AW/9 in Indiana . . . I had the pileup in both ears and my own transmit frequency at lower and off-center just in case my relief operator needed to contact me... or to transmit between the idiots who can't seem to understand what "Listening up 3" means.

3) Listening to my main rag crew frequency in both ears, and having two other slices in the right and left ears respectively.  Making it much easier to determine which frequency I am listening to. The ability to pan any slice to center, full left, full right, or anywhere along the pan placement has been very handy.

4) Having two speakers with the ability to pan the position of any slice adds an additional dimension to the "presence" of the stations I am listening to, and makes them more easy to understand.  But this is my personal experience.

5) There have even been times, using my Bose Companion II series 3, that I had both my Flex6500 and my Flex1500 attached at the same time and was able have one rig in each channel, but quickly move them around the sound field.  Yes, I could have used multiple speaker sets, but I only want one set cluttering my desk.

These are a few reasons I would opt for using dual speakers.  But as long as you properly isolate the unused channel, you can do what you wish.  It's your rig.  I do think you will miss out on one of the advantages of the rig's multiple slice capabilities.

Have fun!

Ken - NM9P

James Kirk

My friend has 7.1 ears

Jim K4JAF

I personally vote for 2 speakers --- Great to hear the pileup in one ear and the DX in the other..

Jim K4JAF

Jim KJ3P

Thanks Jim....(love your moving meter icon)

Jim KJ3P

Ken---Thanks for a thoughtful summary. Actually, you described more hamming in your single reply than I've done since licensed in 1958! I'm just a simple boy, so I plan to start with a mono speaker, but using headphones when dual channels might be beneficial. I'll probably overcome my stubbornness after a while, and wire up both channels to speakers.