[R-390] Can't Post with picture link

[Tony Casorso]

I've tried a dozen butcherings of the link for a photo in my post and it will not go through. The spam filters must be set on high.

Here is my post minus the picture link in it's entirety. If this goes through then some word in the link is triggering the spam filter. I guess you could email me for the link. What a pain.




I couldn't post the following with the picture link intact. I've tried ahlf a dozen butcherings of the URL.  Maybe this ultimate butchering will work. 

You all probably remember the thread I started about my problems with a strong local AM station (groan). I mentioned this problem in another forum and was chastised and told to "fix the radio". Well, I'm still not convinced entirely that my radio is OK and today I swept the front end of the R-390a and compared it to my R-392. I have a picture of the results to share:

LINK REMOVED

The sweeps of the two radios are shown on the same display using the memory feature of the spectrum analyzer. I am sweeping from 0 to 5MHz and both radios are tuned to 3.3MHz. The sharper response with the lower peak is the R-392. The wider, taller response is the R-390a. As I mentioned last time, I can't find anything wrong with the R-390a. The same sort of result is obtained on the 1-2MHz band. I am attributing the higher response of the R-390a to the turns ratio of the front end RF transformers.

In both radios I am monitoring the grid of the first RF stage with the power off using a 10x scope probe. The input signal is about 160mv peak to peak for this picture. I am using the balanced input on the R-390a.

To get the picture I am using the sweep generator to sweep at about 1 or 2 Hz sweep rate and the spectrum analyzer in peak-hold mode.

I have checked for a proper RF ground at the AGC feed point. All resistance checks look correct.

I just can't believe that this is the way it is supposed to look. If somebody else could duplicate the R-390a result (or refute it) I sure would appreciate it.

Thanks,

Tony