The AM Forum

I can't transmit from my present location -- my antenna is in a noisy location and is hidden on a fence only three feet off the ground -- but K4HX had such a big signal on 40 meters this afternoon that I was able to record him in my modified Racal 6790's full 20 kHz bandwidth:

http://liberty.3950.net/K4HX_20111016_0330pm_7295kHz_20kHzBW.mp3 (http://liberty.3950.net/K4HX_20111016_0330pm_7295kHz_20kHzBW.mp3)

Excellent sound, with an intense high end reminiscent of K3ZRF.

73,

Kevin, WB4AIO.

Any sync detect on that, Kevin ?

If not, the reception at this selectivity is all the more impressive with this kind of s/n ratio during certain moments.

It's the standard Racal pseudo-sync detector (some call it a synchrodyne) in which the received signal is heavily limited and then applied to the carrier input of a product detector. It's inferior to a real sync detector. Although it does stay linear with large positive peaks, and it can't ever lose sync, it is no help during deep selective fades compared to a diode, and it causes noticeably more distortion than a diode detector if presented with in excess of 100% negative modulation (actual carrier cutoff).

All the credit goes to Steve for, on peaks at least, providing a full-quieting carrier!

Kevin, WB4AIO.

Where Freq?  7.160 or 7.290ish?



edit:  Nevermind.. I see the header says 7290 :)


" KALIEDOSCOPE FOUR HALF-TRACK XYLOPHONE! "  8)  Beautiful Steve!

WOW Steve must have something BIG there.........and it doesn't sound like a Flex.....200% pos???? I like the room sound....like the old SW broadcast of yesteryear...

Fred

Great sound Steve, as always!

I remember a few years ago putting a 40M element on the antenna at the cabin. Turned on the radio and there you were calling CQ on 7290. Another S9+20 siganiganal!

Great job.

What's amazing to me is the lack of any buzzies, static, TV horizontal, etc.

Thanks for the high quality recording. It's always instructive to hear how your own signal is received another location.

After Todd and I signed, we went and sat on the outside deck for a while and enjoyed the FB WX.

It amazed me too -- especially considering how close the antenna is to a whole row of houses with twenty-five zillion digital devices running at the same time. Raw signal strength is the answer to everything, except maybe love and hunger.

73,


Kevin, WB4AIO.

You're welcome. Your signal looked good on the scope too -- makes me think you are using an effective peak limiter.


Kevin, WB4AIO.

This is basically the only weapon we have left in the arsenal against consumer garbage appliance RFI.
That and special receiving methods involving antennas with deep nulls, and phase shifting/nulling networks.

On-going, having a strapping signal is one of the top ways to stay in the game.  Under top condx and the right time of day etc. 50 w. can still work but averaged out over time, QRO wins.   

I'm seeing this with bc stations in the mw band.  It's getting to the point where the minimum is 5 KW for a listener friendly signal; depends on the tx site, dial spot etc. but even 50 KW stations can get RFI induced signal degredation in their primary coverage areas now.. 

Yes we did! A cold 807, some salsa and chips, and a blue sky, 70-something-and-sunny day that couldn't be beat. Not a bad way to end the Six Days of NEAR-Fest.  ;D

It was pretty amazing how much activity there was on the higher bands Sunday. 10, 15, 20 meters all had plenty of good signals. Even heard a few AM signals on 10.

TNX for posting the recording, Kevin. The fellow who responded to Steve's CQ was returning to the bands after a long hiatus by the sounds. We also talked with Russ, 'FAU on 40 a bit before that.

Good call. Using a CRL PMC 300.

What is your transmitter Steve? Nice sounding rig!

Terry,

Stupid question... Go back and listen to the audio clip AGAIN!

Steve, how do you like the PMC-300?  I've wondered how it compares to the later models.  They show up from time to time on eBay.

Yep, nothing like a strapping signal. The recording below is one of the best SNRs I've heard in a long time, maybe ever. It's Tim - W3TIM on 160 meters in the early evening a few years ago. He is so strong there is almost no noticeable band noise during most of the recording.

I've been using it for something like 14 years. I guess I like it.

You feeding to that 1kD Front, back or Center Steve?

C

I’m feeding the audio directly to the balanced modulator via a jack on the back.

You know Ralph, I went back and listened to the clip again and indeed did get the type of transmitter that he was using. I think it would have been much easier if you would have just reminded me that it was a certain type transmitter rather than to command me to go listen again! I get really offended when anyone uses the word "stupid" when it is in reference to me!

But I still think  your a great guy Ralph ;D ;D ;D

THanks. I ran some tests with my 1Kd a few years back. Once you do that, Its a damn nice AM rig.  Sounded good man!

C