Hello,
I did some "nearby" measurements in different configurations.
20191006_LTZ06_EMI_CW_nearby30_K2000.PNG shows the configuration without any external filtering.
When looking at the resonance frequencies we have 12 and 15 MHz + ~44 MHz.
The 44 MHz correspond to a wavelength of 6.8m. With a shortening factor of 0.95 and a quarter wavelength antenna we have to look for a 1.6 m long wire.
The connection between LTZ#6 and K2000 consists of 2 parts: one 0.6 m the other 0.7 m so with some wire length within the K2000 and the LTZ#6 we can assume a 1.6 m total resonant length.
The 12 and 15 MHz resonances could result from the 100nF capacitors which are on this line (they have typical self resonant frequencies of 10-20 MHz). One 100nF WIMA MKS02 foil capacitor within the LTZ (across the output) and one 100nF ceramic which is in the middle of the 2part connection.
Measurement 20191004_LTZ06_EMI_CW_nearby30_K2000filt.PNG shows what happens if we use a EMI core with 3.5 windings near the K2000. The 12 and 15 MHz peaks are dampened and the 44 MHz peak is shifted towards 48 MHz. (so the effective antenna length has been shorted somewhat).
20191007_LTZ06filt_EMI_CW_nearby30_K2000.PNG shows the EMI-core on the LTZ#6 side. There is only some temperature drift during measurement visible. (the two 10Vss measurements are 3 hours apart).
20191007_LTZ06filt_EMI_CW_nearby30_K2000filt.PNG is similar with EMI-cores on both sides over night so less temperature drift on the K2000.
The large EMI effect seems to be really high frequency effect. The early data from the LTZ6 suggest that the that there are resonances and both #7 and #8 seem to have a resonance (just) higher than the frequency range tested. So the difference between the 2 may be just a minimal different resonance frequency.
The interesting part may be a slightly higher frequency (FM radio).
I am still hoping that someone with better equipment (frequency generator up to 80 or even 230 MHz) tries to repeat some of my tests at least for the LTZ1000. Interesting would also be a comparison to a LTFLU based device.
Sorry but I for my part do not want to spend several 100$ for a frequency range beyond 60 MHz.
And I am shure that the measures that are done for 60 MHz also do some improvement above 60 MHz.
with best regards
Andreas