Re: ERA-3+ Version passes the smoke test


Michael McShan <n5jky@...>
 

No, I have not hacked the DDS yet.  I'll give it a try tomorrow and see what happens.

Mike N5JKY


On Nov 8, 2013, at 9:45 PM, Jerry Haigwood <w5jh@...> wrote:

 

Mike,

    I finished a ERA-3 version tonight.  I measured the output level before installing the final attenuator and found that I had +7.4 dbm output.  So, my final attenuator value is -17 db.  I am surprised that there is that much difference in the output levels.  Did you remove the DDS low pass filter?  I would really like to see where the output level difference is coming from.

Jerry W5JH

"building something without experimenting is just solder practice"

 

From: PHSNA@... [mailto:PHSNA@...] On Behalf Of Michael McShan
Sent: Friday, November 08, 2013 8:18 PM
To: PHSNA@...
Subject: [PHSNA] ERA-3+ Version passes the smoke test

 

 

Well, my build seems to have passed the smoke test OK. I was able to program it to sweep between 2000 khz and 10000 khz with 500 hz steps and watch the output on my O-scope and frequency counter. The output looks like an OK sine wave. The -10 dBm output is exactly that on my W7ZOI/W7PUA power meter and the output before R19 is 0 dBM. My little homebrew bench frequency counter is a bit "deaf," so I probably will remove this resistor for the counter output (unless there is a compelling reason not to).

I noticed that R7 did get kind of warm, so I may replace the 1/2W one with a 1W version. Seems like a good idea.

Now I have to start thinking about making a case for this FB project.

Thank you, Jim and Jerry! Well done, gentlemen.

73, Mike N5JKY
OK City

Join PHSNA@groups.io to automatically receive all group messages.