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Each 'port' has 16 locked screws to adjust. The 'low' port passes 2020-2080 in a similar fashion.
I recall reading somewhere that you need patience and kit to do this correctly. I'd guess that unscrewing each screw say 45 degrees would move the passband up. Ripple and such can then be optimised as long as patience allows.......
Or, build a 'Stop-end pipe cap' filter(s) like these http://www.ko4bb.com/ham_radio/Pipe_Cap_Filters although as we are metricated I can get either 22 or 28mm i.d. caps for sensible money via eBay. I've plenty of hardline SMA patch leads I can sacrifice to build them. The larger '11/2"' start to cost silly money.
Anyone able to comment.....on either routes? Application is crud filter before big PA on 13cm.
- 13cm band pass.jpg (129.18 KiB) Viewed 756 times
Someone has made a video of a similar technique:
I have a NanoVNA but that is yet to be software expanded upwards beyond 900MHz although its performance at 2.4GHz might leave a bit to be desired. I think I'll have a crack at the low pass side first, as that is currently of no use on 13cm so if I mess it up its not a 'loss' as such. Being able to watch the PB live should provide the visual feedback I need. Got to remove the 'glue' from 16 screws first
http://g4guo.blogspot.com/2015/11/using ... ry-to.html
however for those that are interested a Google for AN 1287-8 will find the document from a non Keysight address.
I think that is obvious from the S11 and S22 plots on my blog.
My HP VNA didn't come fitted with a licence for TDR but there was a guy in the HP group that can create
a licence provided it is for non commercial use. I think that DG8SAQ VNWA 3 software supports TDR.
Even it you don't intend to use TDR it is as you say an interesting paper to read.
For the next one I'll lock a couple of nuts on the end as per the guidance here http://www.ko4bb.com/ham_radio/Pipe_Cap_Filters/
At the moment I only have threaded steel rod, but the BW and insertion loss are what I would think is quite reasonable as-is. Before I turn down and thread some brass, will it make any difference?
Trace from Satsagen. Its great Gareth