[time-nuts] WG mounting h/w (2)
Hi, Well, still not strictly, strictly true ! In Ku K band earth stations I've worked in, I've never seen shoulder screws used, although the equipment used was mainnly from the USA. Next to you precision adaptors, SMA torque wrenches etc in your personal goodie box are sets of tapered pins, about 35-40mm long - that fit various diameter WG mounting holes (the old metric vvs Imperial issue again). You insert a pair of pins on diagonal corners then add bog-standard SS hardware to the opposite diagonals tighten. The tapered pins are then removed and replaced with another pair of screws/nuts. This ensures absolute (?) internal WG slot alignment. There are a few variations on this theme if you must have absolutely minimum RL within that section of guide or if one guide face is threaded. Hex-headed bolts are usually used. That may explain why shouldered bolts are seldom seen. Tapered WG pins fall into the 99.% unobtainium class of materials. Kit VK2LL -- Message: 6 Date: Sun, 19 Sep 2010 10:15:17 + (GMT) From: Robert Atkinson robert8...@yahoo.co.uk Subject: Re: [time-nuts] Semi-OT: Hardware for WR-90 waveguide sections? To: Discussion of precise time and frequency measurement time-nuts@febo.com Message-ID: 414785.76181...@web27102.mail.ukl.yahoo.com Content-Type: text/plain; charset=iso-8859-1 Hi, Not strictly true. Material is not important apart from environmental (corrosion) issues, but that is not the only concern. WG-16 (British) / WR 90 flanges are not dowelled. They rely on the fastners for alignment. The correct fastners are 5/32 shoulder screws (0.1557 dia 6-32 thread). snip ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WG mounting h/w (2)
Another mystery solved! My (late) father-in-law spent most of his career at Varian-Eimac, mostly working on TWTs, BWOs, and the occasional magnetron. In one batch of his goodies, along with the HS SMA torque wrench, was a little box with some tapered metal pins! I've wondered what those were for, and now I know! He was very happy when his daughter brought home someone who knew what vacuum tubes were, even if he did think that the RF work I did as a ham, even the 144 and 440 MHz stuff, was still practically DC... Bob K6RTM -- Message: 2 Date: Mon, 20 Sep 2010 08:19:25 + From: Kit Scally ksca...@bytecan.com.au Subject: [time-nuts] WG mounting h/w (2) To: time-nuts@febo.com time-nuts@febo.com Message-ID: 2ab674d4b0c99d4ca524e8530ba1b87c08dc5...@msg02nsw.bytecan.com.au Content-Type: text/plain; charset=us-ascii Hi, Well, still not strictly, strictly true ! In Ku K band earth stations I've worked in, I've never seen shoulder screws used, although the equipment used was mainnly from the USA. Next to you precision adaptors, SMA torque wrenches etc in your personal goodie box are sets of tapered pins, about 35-40mm long - that fit various diameter WG mounting holes (the old metric vvs Imperial issue again). You insert a pair of pins on diagonal corners then add bog-standard SS hardware to the opposite diagonals tighten. The tapered pins are then removed and replaced with another pair of screws/nuts. This ensures absolute (?) internal WG slot alignment. There are a few variations on this theme if you must have absolutely minimum RL within that section of guide or if one guide face is threaded. Hex-headed bolts are usually used. That may explain why shouldered bolts are seldom seen. Tapered WG pins fall into the 99.% unobtainium class of materials. Kit VK2LL ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WG mounting h/w (2)
I'm not so sure the alignment pins are unobtanium. I think they are just common Taper Pins: http://www.reidsupply.com/GrpResults.aspx?st=TAPER+PINpid=0aitm=GLH-503apid=0bi= -John == Another mystery solved! My (late) father-in-law spent most of his career at Varian-Eimac, mostly working on TWTs, BWOs, and the occasional magnetron. In one batch of his goodies, along with the HS SMA torque wrench, was a little box with some tapered metal pins! I've wondered what those were for, and now I know! He was very happy when his daughter brought home someone who knew what vacuum tubes were, even if he did think that the RF work I did as a ham, even the 144 and 440 MHz stuff, was still practically DC... Bob K6RTM -- Message: 2 Date: Mon, 20 Sep 2010 08:19:25 + From: Kit Scally ksca...@bytecan.com.au Subject: [time-nuts] WG mounting h/w (2) To: time-nuts@febo.com time-nuts@febo.com Message-ID: 2ab674d4b0c99d4ca524e8530ba1b87c08dc5...@msg02nsw.bytecan.com.au Content-Type: text/plain; charset=us-ascii Hi, Well, still not strictly, strictly true ! In Ku K band earth stations I've worked in, I've never seen shoulder screws used, although the equipment used was mainnly from the USA. Next to you precision adaptors, SMA torque wrenches etc in your personal goodie box are sets of tapered pins, about 35-40mm long - that fit various diameter WG mounting holes (the old metric vvs Imperial issue again). You insert a pair of pins on diagonal corners then add bog-standard SS hardware to the opposite diagonals tighten. The tapered pins are then removed and replaced with another pair of screws/nuts. This ensures absolute (?) internal WG slot alignment. There are a few variations on this theme if you must have absolutely minimum RL within that section of guide or if one guide face is threaded. Hex-headed bolts are usually used. That may explain why shouldered bolts are seldom seen. Tapered WG pins fall into the 99.% unobtainium class of materials. Kit VK2LL ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WG mounting h/w (2)
I think you are a snip too soon. My original post said If you have to use screws, at least align two diagonal holes with 5/32 dowels while nipping up the first two screws. Taper pins are also OK of the taper is slight and flanges are not too thick. Don't tighten the first two screws too tight at first to aviod warping the flange. In aircraft installations I've designed have used shoulder screws because they were specified by the equipment manufacturer. Robert G8RPI. --- On Mon, 20/9/10, Kit Scally ksca...@bytecan.com.au wrote: From: Kit Scally ksca...@bytecan.com.au Subject: [time-nuts] WG mounting h/w (2) To: time-nuts@febo.com time-nuts@febo.com Date: Monday, 20 September, 2010, 9:19 Hi, Well, still not strictly, strictly true ! In Ku K band earth stations I've worked in, I've never seen shoulder screws used, although the equipment used was mainnly from the USA. Next to you precision adaptors, SMA torque wrenches etc in your personal goodie box are sets of tapered pins, about 35-40mm long - that fit various diameter WG mounting holes (the old metric vvs Imperial issue again). You insert a pair of pins on diagonal corners then add bog-standard SS hardware to the opposite diagonals tighten. The tapered pins are then removed and replaced with another pair of screws/nuts. This ensures absolute (?) internal WG slot alignment. There are a few variations on this theme if you must have absolutely minimum RL within that section of guide or if one guide face is threaded. Hex-headed bolts are usually used. That may explain why shouldered bolts are seldom seen. Tapered WG pins fall into the 99.% unobtainium class of materials. Kit VK2LL -- Message: 6 Date: Sun, 19 Sep 2010 10:15:17 + (GMT) From: Robert Atkinson robert8...@yahoo.co.uk Subject: Re: [time-nuts] Semi-OT: Hardware for WR-90 waveguide sections? To: Discussion of precise time and frequency measurement time-nuts@febo.com Message-ID: 414785.76181...@web27102.mail.ukl.yahoo.com Content-Type: text/plain; charset=iso-8859-1 Hi, Not strictly true. Material is not important apart from environmental (corrosion) issues, but that is not the only concern. WG-16 (British) / WR 90 flanges are not dowelled. They rely on the fastners for alignment. The correct fastners are 5/32 shoulder screws (0.1557 dia 6-32 thread). snip ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
