The AM Forum

Just picked this up from Tim  WA1HLR.  Here are recordings.  One high power at 75 watts and low (for linear drive) at 15 watts.  The mic is a D-104 straight into the V1

Al

Al,

  Nice recordings. So who is that old guy doing the talking?  ;D

Listening to the MP3's with my laptop, and (2$ Jet Blue) headphones, I think there is a bit much pre-emphasis. With Windows media player, and the built in equalizer, I can make you sound really good. I show the settings in the attached file.

Thinking about it, many receivers will drop the lows, and the highs, and your current settings might be about right for many, but not all receiver situations. You certainly cannot please everybody, so at some point, at least me, I dial it the way I want it, and then transmit.

It would be interesting to see that 32V on the scope, as I bet it might over modulate easier at 3 Khz well before then at 1 Khz and down. After I equalized things at my end, you were broadcast quality.

Jim
WD5JKO

Listening right now on d air.

Sounds very nice.

Al,

I was just listening to this on the laptop with the yellowie internal speaker so it basically sounded the same to me each way.  That is probably due to my laptop.  I would imagine that the the rig would be capable of a bit more low end while on the low voltage tap.  Not as much current flowing through the mod iron.  I know on the Ranger it makes a big difference on the low end when running the LV supply through the secondary of the mod iron.  Not having a lot of experience with the 32V series of transmitters not sure how that mod iron reacts to lesser current through the secondary. 

My request is to run as much power as you can so you can be heard well down here in S.E. PA!

When we have worked I believe you voice does better with some good pre-emphsis and not a big low end.  Helps clarity a lot especially when your 5-7 or so otherwise its kind of mushy.     

Joe, W3GMS     

Al, on my computer monitor here, there seems to be a nasty peak up around 4K, very grainy. But that's basic Windows Media Player.

Overall the distribution from lows to highs isn't as good as a 32V can sound.

Let me open up those files into a program that measures (by frequency range) where the audio is concentrated.

Both low and high power sound the same.  My experience on a 32V2 is that the best match between the 807s and the 4D32 comes with the 700V setting, lightly loaded, and I have an external grid drive control to keep the RF drive within spec.

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A quick look in the audio application Audacity.

I messed with some equalization where I thought it was peaky, and warmed up the lower midrange.  See if you prefer this.  The screen shot shows the adjustments I made to the original sound file.