I have to keep reminding myself: This is not "plug and play." These are not appliances.
After I got my 40 meter problems squared away, I was doing some testing on my beloved 17 meter BITX. I noticed something weird: With the CCI EB63A amp feeding my 17 meter Moxon antenna, as I raised the output of the BITX17 driver, at one point (at about half the max input power) the SWR would suddenly spike. Then, as I raised the drive level above that point, the SWR would go back to normal.
I looked at it on the 'scope. I can see the signal go very ugly at the mid-level drive point. In the FFT display, I can see that there is a strong signal at around 435 kHz. The 18 MHz signal seems to be riding along on top of it. Take a look at the video above.
I see no signs of the 435 kHz signal at the output of the BITX 17. It seems quite clean.
This problem disappears if I replace the Moxon with a dummy load.
This problem does not show up if I feed the EB63A with my almost identical BITX20. And I use the same LP filter on both 20 and 17 in the CCI amp.
Any suggestions? Has anyone had this kind of problem?
Allison and Pete have been helping me with this. Thanks to both of them.
In response to popular demand, "SolderSmoke -- Global Adventures in Wireless Electronics" is now available as an e-book for Amazon's Kindle.
Here's the site:
For the print version:
For shipping from a printer in the U.S. (probably better for N. American buyers) Click here: SolderSmoke USA Version
For shipping from a printer in the UK, Spain, or the USA (probably better for UK and other European buyers)
Click here: SolderSmoke EU Version
The two versions are identical, except for a minor difference in the paper used. That's why the prices are a bit different.
Bill's OTHER Book (Warning: Not About Radio)
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W4HBK's QRSS Grabber: The Amazing Pensacola Snapper (Live!)