Re: trick to soldering in L5 and L7 or why did spurs on 80/40 get worse and 20/10 get better...


Mark I have both S+M and A T, both are working fine on my many test boards.
Every board is very individual in behaviour. I have some which put out lots of power
and some low power out. I have not figured out why as yet.

Some boards I changed only L5 and that was enough. Any RF pickup by L7 is removed by
the filter Y1 during TX.


At 24-06-19, you wrote:

Thank you very much!

However, I am worried that the inductors I have are not the exact same ones you used. I got them from another HAM that ordered them thru the same supplier that you used, but EBAY suppliers have been know to substitute.

Mine are orange/yellow and are marked "A" and "T" and R68K 1145. However, in your post#60946 you said that they were Marked "S+M". I assume the 68k means 680nh? Perhaps the A+T vs S+M is a country/manufacturing plant?


I suspect that the apparent power loss on 80/40 is not true. I measured harmonics/spurs 4x. For the Primary:

Band                    1st                     2nd                      3rd                         4th (after l5/l7 replaced)
80                       -65                       -64                      -57                        -65
40                       -67                       -67                      -65                        -70

80M looks like man outlier. And i really don't knew what i am doing with the SDRPLAY spectrum scope software, so mistakes could creep in.

40M does look lower after inductors. I am going to re-measure later today.


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