Re: [time-nuts] time-nuts Digest, Vol 117, Issue 80
Hi Yup, little high spots on the corners of the metal plates. Put the plates in “upside down” and the crystal stopped working …. — If you want to dig into the WWII stuff Virgil Bottom was always happy to talk about his role in saving the world by fixing the crystal process. There are a variety of stories told, some similar to his, some quite different. Yes beer was often involved during the story telling. Who knows what really happened ….. Bob On Apr 21, 2014, at 1:30 PM, johncr...@aol.com wrote: > > The FT-243 holders I revamped in the 1950s and 60s did have the > aforementioned spring. However a close look at the electrode plates that > contacted the quartz resonator had, in every case, a raised boss at each > corner that spaced the center of the electrode a few mills above the center > of the quartz. So the center part of the quartz was not restrained from > moving. And it was not compressed by the spring. > > As I recall the stack up was lower electrode, quartz resonator (square in the > case of the FT-243) upper electrode, edge seal with hole for the spring, the > spring, and then the cover. > > I reworked quite a few of these at 8 MHz for use on the 2 meter band by > multiplying by 18X. 8 x 18 = 144 MHz. Tooth paste moved them up and a small > scratch with a bit of solder moved them down. > > > > > Re: optically excite a quartz crystal? (Bob Camp) > > > > As for Bliley - go to the web site and if you look around, you can find a > fascinating history of the company. It included details of the invention of > the etch process and also of the "rubber rock" technique to vary the > frequency of a crystal. > > They still make some of the best resonators for custom designed oscillators > around. I used them last in a synthesizer design for a FAA customer VHF/UHF > receiver only about 6 years ago. > > -73 john k6iql > > > > -Original Message- > From: time-nuts-request > To: time-nuts > Sent: Mon, Apr 21, 2014 11:00 am > Subject: time-nuts Digest, Vol 117, Issue 80 > > > Send time-nuts mailing list submissions to > time-nuts@febo.com > > To subscribe or unsubscribe via the World Wide Web, visit > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > or, via email, send a message with subject or body 'help' to > time-nuts-requ...@febo.com > > You can reach the person managing the list at > time-nuts-ow...@febo.com > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of time-nuts digest..." > > > Today's Topics: > > 1. Re: optically excite a quartz crystal? (Bob Camp) > 2. Re: optically excite a quartz crystal? (Bob Camp) > > > -- > > Message: 1 > Date: Mon, 21 Apr 2014 11:24:43 -0400 > From: Bob Camp > To: Poul-Henning Kamp > Cc: Discussion of precise time and frequency measurement > > Subject: Re: [time-nuts] optically excite a quartz crystal? > Message-ID: <402dec2b-2405-493a-9866-31cc2ca88...@rtty.us> > Content-Type: text/plain; charset=windows-1252 > > Hi > > As with all ?good stories? there are many versions told by many people. I?ve > heard far to many mutually contradictory versions to have any real idea > what?s > true. You are correct that etching was a known process in the 1930?s and that > it > had been used by various people at various times. Since it added time (and > complexity) to the process, it got dropped by most people to speed up > production > ? > > Bob > > On Apr 21, 2014, at 10:51 AM, Poul-Henning Kamp wrote: > >> In message , Bob Camp writes: >> >>> Early in the WWII era, quartz blanks were not commonly etched after >>> begin ground / polished to frequency. This left debris on the surface >>> of the blank. The net result was that the resonators failed after >>> a period of time in the field, especially under damp conditions. >>> The problem got so bad that it actually threatened the ability to >>> communicate in 1942. A fairly high level team looked into the issue >>> and etching of blanks (and a few other mods) were made a mandatory >>> part of all crystals suppled to the government. >> >> The story is slightly more interesting than that: >> >> Blileys crystals were almost totally without these problems, but >> they wouldn't tell why that might be. >> >> In the end the government put a lot of pressure on Bliley to squeeze >> out the manufacturing secret. >> >> The secret was etching. >> >> To keep it secret, Bliley had called it something along the lines >> of "X-Grind" and not applied for a patent. >> >> The Government forced Bliley to share the etching secret without >> giving any compensation, and the Blileys were bitter about that for >> the rest of their lifes. >> >> -- >> Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 >> p...@freebsd.org | TCP/IP since RFC 956 >> FreeBSD committer | BSD since 4.3-tahoe >> Never attribute to
Re: [time-nuts] time-nuts Digest, Vol 117, Issue 80
The FT-243 holders I revamped in the 1950s and 60s did have the aforementioned spring. However a close look at the electrode plates that contacted the quartz resonator had, in every case, a raised boss at each corner that spaced the center of the electrode a few mills above the center of the quartz. So the center part of the quartz was not restrained from moving. And it was not compressed by the spring. As I recall the stack up was lower electrode, quartz resonator (square in the case of the FT-243) upper electrode, edge seal with hole for the spring, the spring, and then the cover. I reworked quite a few of these at 8 MHz for use on the 2 meter band by multiplying by 18X. 8 x 18 = 144 MHz. Tooth paste moved them up and a small scratch with a bit of solder moved them down. Re: optically excite a quartz crystal? (Bob Camp) As for Bliley - go to the web site and if you look around, you can find a fascinating history of the company. It included details of the invention of the etch process and also of the "rubber rock" technique to vary the frequency of a crystal. They still make some of the best resonators for custom designed oscillators around. I used them last in a synthesizer design for a FAA customer VHF/UHF receiver only about 6 years ago. -73 john k6iql -Original Message- From: time-nuts-request To: time-nuts Sent: Mon, Apr 21, 2014 11:00 am Subject: time-nuts Digest, Vol 117, Issue 80 Send time-nuts mailing list submissions to time-nuts@febo.com To subscribe or unsubscribe via the World Wide Web, visit https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts or, via email, send a message with subject or body 'help' to time-nuts-requ...@febo.com You can reach the person managing the list at time-nuts-ow...@febo.com When replying, please edit your Subject line so it is more specific than "Re: Contents of time-nuts digest..." Today's Topics: 1. Re: optically excite a quartz crystal? (Bob Camp) 2. Re: optically excite a quartz crystal? (Bob Camp) -- Message: 1 Date: Mon, 21 Apr 2014 11:24:43 -0400 From: Bob Camp To: Poul-Henning Kamp Cc: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] optically excite a quartz crystal? Message-ID: <402dec2b-2405-493a-9866-31cc2ca88...@rtty.us> Content-Type: text/plain; charset=windows-1252 Hi As with all ?good stories? there are many versions told by many people. I?ve heard far to many mutually contradictory versions to have any real idea what?s true. You are correct that etching was a known process in the 1930?s and that it had been used by various people at various times. Since it added time (and complexity) to the process, it got dropped by most people to speed up production ? Bob On Apr 21, 2014, at 10:51 AM, Poul-Henning Kamp wrote: > In message , Bob Camp writes: > >> Early in the WWII era, quartz blanks were not commonly etched after >> begin ground / polished to frequency. This left debris on the surface >> of the blank. The net result was that the resonators failed after >> a period of time in the field, especially under damp conditions. >> The problem got so bad that it actually threatened the ability to >> communicate in 1942. A fairly high level team looked into the issue >> and etching of blanks (and a few other mods) were made a mandatory >> part of all crystals suppled to the government. > > The story is slightly more interesting than that: > > Blileys crystals were almost totally without these problems, but > they wouldn't tell why that might be. > > In the end the government put a lot of pressure on Bliley to squeeze > out the manufacturing secret. > > The secret was etching. > > To keep it secret, Bliley had called it something along the lines > of "X-Grind" and not applied for a patent. > > The Government forced Bliley to share the etching secret without > giving any compensation, and the Blileys were bitter about that for > the rest of their lifes. > > -- > Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 > p...@freebsd.org | TCP/IP since RFC 956 > FreeBSD committer | BSD since 4.3-tahoe > Never attribute to malice what can adequately be explained by incompetence. -- Message: 2 Date: Mon, 21 Apr 2014 11:26:16 -0400 From: Bob Camp To: j...@quikus.com, Discussion of precise time and frequency measurement Subject: Re: [time-nuts] optically excite a quartz crystal? Message-ID: <6b374045-7b1f-4706-8b38-609b4366b...@rtty.us> Content-Type: text/plain; charset=windows-1252 Hi Well I can name at least one post war ham (me at age 14) who did not understand the need for etch after grinding? Bob On Apr 21, 2014, at 11:21 AM, J. Forster wrote: > The etching referred to was by post-war hams, > > -John > > === > > > >> Hi >> >> Early in the WWII era, quartz
