Coax Filters - 23cm etc.


Simon G8DMN
 

Thanks to Neil G4DBN for his talk on machining, oh for a workshop like that! The filter design spreadsheet from F1FRV doesn't seem to be available, the links are not working at the moment. Anyone have a copy? 
I built a filter using dimensions from changpuak.ch, but these don't appear to allow for the extra capacitance from the sides of the larger discs. I had to machine a bit off each disc - tricky when it's all soldered together.
73,
Simon


Neil Smith G4DBN
 

Looks like his site has gone.

My version for 23cm 9 pole LPF is at http://www.g4dbn.uk/?p=517 with a new link to my copy of his spreadsheet for the 9 pole coax LPF and a link to the Internet Archive for the main page.

I don't have the other spreadsheet examples for different filter classes, but I can try asking on the hyperfr forums.

Neil G4DBN


On 15/10/2021 11:42, Simon G8DMN via groups.io wrote:
Thanks to Neil G4DBN for his talk on machining, oh for a workshop like that! The filter design spreadsheet from F1FRV doesn't seem to be available, the links are not working at the moment. Anyone have a copy? 
I built a filter using dimensions from changpuak.ch, but these don't appear to allow for the extra capacitance from the sides of the larger discs. I had to machine a bit off each disc - tricky when it's all soldered together.
73,
Simon
_


Dominique Dehays
 

Hi all ,


looks like there are server problems , try to ask F1FRV directly

f1frv@...

he is a nice guy ( not only because of his nice 1st name)

73

Dom


Le 15/10/2021 à 13:29, Neil Smith G4DBN a écrit :

Looks like his site has gone.

My version for 23cm 9 pole LPF is at http://www.g4dbn.uk/?p=517 with a new link to my copy of his spreadsheet for the 9 pole coax LPF and a link to the Internet Archive for the main page.

I don't have the other spreadsheet examples for different filter classes, but I can try asking on the hyperfr forums.

Neil G4DBN


On 15/10/2021 11:42, Simon G8DMN via groups.io wrote:
Thanks to Neil G4DBN for his talk on machining, oh for a workshop like that! The filter design spreadsheet from F1FRV doesn't seem to be available, the links are not working at the moment. Anyone have a copy? 
I built a filter using dimensions from changpuak.ch, but these don't appear to allow for the extra capacitance from the sides of the larger discs. I had to machine a bit off each disc - tricky when it's all soldered together.
73,
Simon
_


Simon G8DMN
 

Thanks, both.
The discontinuity correction graph comes from a 1944 ProcIRE paper which can be downloaded from https://worldradiohistory.com/hd2/IDX-Site-Technical/Engineering-General/Archive-IRE-IDX/IDX/40s/IRE-1944-11-OCR-Page-0080.pdf one page at a time. I've put the whole thing in the 'Files' tab : WhinneryJamiesonRobbins.zip. Thankfully F1FRV has done the hard work for us for these filters.
73,
Simon


G8DQX list
 

Or extracted from https://worldradiohistory.com/Archive-IRE/40s/IRE-1944-11.pdf <https://worldradiohistory.com/Archive-IRE/40s/IRE-1944-11.pdf>, using a PDF manipulation program.

73, HTH, Stay Safe,

Robin, G8DQX

On 15/10/2021 14:57, Simon G8DMN via groups.io wrote:
Thanks, both.
The discontinuity correction graph comes from a 1944 ProcIRE paper which can be downloaded from https://worldradiohistory.com/hd2/IDX-Site-Technical/Engineering-General/Archive-IRE-IDX/IDX/40s/IRE-1944-11-OCR-Page-0080.pdf <https://worldradiohistory.com/hd2/IDX-Site-Technical/Engineering-General/Archive-IRE-IDX/IDX/40s/IRE-1944-11-OCR-Page-0080.pdf> one page at a time. I've put the whole thing in the 'Files' tab : WhinneryJamiesonRobbins.zip. Thankfully F1FRV has done the hard work for us for these filters.
73,
Simon


Neil Smith G4DBN
 

Dominique F1FRV says there is a temporary server fault and the site has been off for a week. He hopes it will be back soon.

Neil G4DBN

On 15/10/2021 13:48, Dominique Dehays wrote:

Hi all ,


looks like there are server problems , try to ask F1FRV directly

f1frv@sfr.fr

he is a nice guy ( not only because of his nice 1st name)