[Drakelist] Changing Crystal frequency...Penning
HI, Not sure if I can post to this list, I have tried for years... This talk of changing crystal frequencies is great. Do you guys know about penning?? Google it. I learned about it on the Softrock40 group. You can take a cheap ( $1.00) computer crystal and change its frequency down by HUNDREDS of KHz! You just open it up (I use a Dremel with a cutoff wheel) and write on the crystal with a Sharpie Permenant marker. Just go little mark by little mark (and wait for it to dry) and you can make a custom crystal for any frequency you want (well, depending... look at all the crystals available that are just a little higher in frequency).. 73, Gary WB6OGD___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Changing crystal frequency
Right, I had forgotten solder. It's all about mass! :-) 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line and TR-4/C Service Supplement CDs www.k4oah.com lee wrote: Rubbing solder on instead of graphite works a little better as the lead has more mass then graphite. Thus, the oscillations are slightly less and the lead can lower the frequency slightly more then graphite. Lee Bahr, w0vt -Original Message- From: Neil M Califano Sent: Friday, September 16, 2011 7:05 PM To: Drakelist@zerobeat.net Subject: [Drakelist] Changing crystal frequency Someone I know used to write on crystals with a pencil claiming the frequency could be changed. Is this true or an urban legend, because graphite is crystalline? ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Changing crystal frequency
Hi Guys, I *used* to believe that the hermetically sealed HC-6 type of crystals were impervious to aging changing frequency over time---until I started to seriously play around with the old Heathkit SB-line of receivers transmitters, that is! (THAT'S when I learned why the hairline cursor on the analog dial read-out is adjustable on those rigs! Hi Hi). Drake equipment from that same era is certainly not immune to the issue of aging crystals. Proof of the pudding is when you band jump, leaving the PTO alone: amazing how much the cursor has to be re-set on some bands to still be able to copy the 100-KHz crystal calibrator. But that's little hardship, both the Heath Drake engineers took that into account by way of incorporating these features. What can REALLY be vexing, though, is when the crystal(s) used in carrier-generating oscillator frequencies migrate: I once had an SB-102 transceiver that sounded very tinny nasal-sounding on LSB only---much to my chagrin, THAT carrier generating crystal had shifted just enough so as to put a goodly portion of my signal REMOVED from the passband of the IF filter! No amount of dial tweaking / cursor re-adjustment would cure THAT condition! : ) ~73~ de Eddy VE3CUI - VE3XZ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Changing crystal frequency
Eddie - Yeah, but with the Drakes you not only get a 'tinny' sounding sideband, you can always choose the other 'bassy' sideband! :-) There is nothing that beats a NEW 'set' of crystals for a Drake receiver from ICM. You can just switch up the bands on the calibrator, and _may_ get a low audio tone on one or the other. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line and TR-4/C Service Supplement CDs www.k4oah.com Eddy Swynar wrote: Drake equipment from that same era is certainly not immune to the issue of aging crystals. Proof of the pudding is when you band jump, leaving the PTO alone: amazing how much the cursor has to be re-set on some bands to still be able to copy the 100-KHz crystal calibrator. What can REALLY be vexing, though, is when the crystal(s) used in carrier-generating oscillator frequencies migrate: I once had an SB-102 transceiver that sounded very tinny nasal-sounding on LSB only---much to my chagrin, THAT carrier generating crystal had shifted just enough so as to put a goodly portion of my signal REMOVED from the passband of the IF filter! ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Changing crystal frequency
What can REALLY be vexing, though, is when the crystal(s) used in carrier-generating oscillator frequencies migrate: I once had an SB-102 transceiver that sounded very tinny nasal-sounding on LSB only---much to my chagrin, THAT carrier generating crystal had shifted just enough so as to put a goodly portion of my signal REMOVED from the passband of the IF filter! Same issue I have with my Collins 75S-3C. LSB audio in the fixed BFO position does not have the same audio passband characteristics as USB. Even small changes (e.g., 50 Hz) can have a profound effect on the tone of the recovered audio. Unlike the R-4C where its two BFO crystals operate at 10x that of a 455 kHz BFO, the 75S-3 has no variable compensating caps to adjust the crystals' operating frequency. However, when switched to variable BFO mode, all is well and the audio tone can be adjusted with the BFO control. INRAD sells replacement BFO crystals for the 75S-3, so I'll likely try those and see if that improves the fixed BFO audio. Paul, W9AC ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Changing crystal frequency
On Sat, 17 Sep 2011 10:10:53 -0400, Eddy Swynar wrote: What can REALLY be vexing, though, is when the crystal(s) used in carrier-generating oscillator frequencies migrate: I once had an SB-102 transceiver that sounded very tinny nasal-sounding on LSB only---much to my chagrin, THAT carrier generating crystal had shifted just enough so as to put a goodly portion of my signal REMOVED from the passband of the IF filter! I always wondered why some manufacturers didn't put adjustment trimmers in the carrier oscillator curcuit. This is one of the most critical adjustments in a SSB radio, and I'm a-r enough about it these days that I check my frequency counter agianst a rubidium standard before I make adjustments. I actually added trimmer caps to the HW-101 that I had years ago so I could get it right. 73 -Jim -- Ham Radio NU0C Lincoln, Nebraska, U.S.S.A. TR7/RV7/R7A/L7, TR6/RV6, T4XC/R4C/L4B, NCL2000, SB104A, R390A, GT550A/RV550A, HyGain 3750, IBM PS/2 - all vintage, all the time! Give a man a URL, and he will learn for an hour; teach him to Google, and he will learn for a lifetime. HyGain 3750 User's Group - http://groups.yahoo.com/group/HyGain_3750/ http://incolor.inetnebr.com/jshorney http://www.nebraskaghosts.org ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Changing crystal frequency
The problem is that just about any trimmer cap you choose is going to be less 'stable' LONG TERM than the crystal. So the good news is that you can adjust the frequency, the bad news is that you're going to have to! No trimmer is going to be as stable as a good crystal, and since most electronic stuff doesn't LAST for 50 years, you're better off without a trimmer. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line and TR-4/C Service Supplement CDs www.k4oah.com Jim Shorney wrote: On Sat, 17 Sep 2011 10:10:53 -0400, Eddy Swynar wrote: What can REALLY be vexing, though, is when the crystal(s) used in carrier-generating oscillator frequencies migrate: I once had an SB-102 transceiver that sounded very tinny nasal-sounding on LSB only---much to my chagrin, THAT carrier generating crystal had shifted just enough so as to put a goodly portion of my signal REMOVED from the passband of the IF filter! I always wondered why some manufacturers didn't put adjustment trimmers in the carrier oscillator curcuit. This is one of the most critical adjustments in a SSB radio, and I'm a-r enough about it these days that I check my frequency counter agianst a rubidium standard before I make adjustments. I actually added trimmer caps to the HW-101 that I had years ago so I could get it right. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Changing crystal frequency
One other thing as far as Carrier Oscillator crystals. With a little care, you can almost always set the frequency 'better' by ear for best audio, especially since the _CRYSTALS_ inside filters also change, altering the overall shape of the passband slightly. Especially with the Drake where even the BEST adjustment is a compromise. I'd be willing to bet that very few radios would be at their optimum 'sound quality' by setting the CO crystal to a specific frequency, no matter how many places came after the decimal point! :-) 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line and TR-4/C Service Supplement CDs www.k4oah.com Jim Shorney wrote: On Sat, 17 Sep 2011 10:10:53 -0400, Eddy Swynar wrote: What can REALLY be vexing, though, is when the crystal(s) used in carrier-generating oscillator frequencies migrate: I once had an SB-102 transceiver that sounded very tinny nasal-sounding on LSB only---much to my chagrin, THAT carrier generating crystal had shifted just enough so as to put a goodly portion of my signal REMOVED from the passband of the IF filter! I always wondered why some manufacturers didn't put adjustment trimmers in the carrier oscillator curcuit. This is one of the most critical adjustments in a SSB radio, and I'm a-r enough about it these days that I check my frequency counter agianst a rubidium standard before I make adjustments. I actually added trimmer caps to the HW-101 that I had years ago so I could get it right. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Changing crystal frequency
On Sat, 17 Sep 2011 11:27:58 -0400, Garey Barrell wrote: The problem is that just about any trimmer cap you choose is going to be less 'stable' LONG TERM than the crystal. So the good news is that you can adjust the frequency, the bad news is that you're going to have to! No trimmer is going to be as stable as a good crystal, and since most electronic stuff doesn't LAST for 50 years, you're better off without a trimmer. Are you telling me that you only touch up your alignments every 50 years? :O 73 -Jim -- Ham Radio NU0C Lincoln, Nebraska, U.S.S.A. TR7/RV7/R7A/L7, TR6/RV6, T4XC/R4C/L4B, NCL2000, SB104A, R390A, GT550A/RV550A, HyGain 3750, IBM PS/2 - all vintage, all the time! Give a man a URL, and he will learn for an hour; teach him to Google, and he will learn for a lifetime. HyGain 3750 User's Group - http://groups.yahoo.com/group/HyGain_3750/ http://incolor.inetnebr.com/jshorney http://www.nebraskaghosts.org ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Changing crystal frequency
GM All: Interesting that my FT-890 just off the repair bench has the capability to offset the transmit carrier relative to the passband + or - individually for USB and LSB. One does this by monitoring the signal in the internal monitor or a second rx to adjust the tx audio. Since the rig is a master reference osc/PLL the offsets are in memory. This is instead of having a true audio equalizer on board. Actually works pretty well except that it can't boost or cut at both ends of the bandwidth. Does work well for fixing a bassy or trebley mic. Same thing that Garey is saying tho. best adjustment is a compromise by ear. to se the carrier point. I have a great counter with TCXO reference and oven, but final set points on ALL my alignments are done by ear. FWIW Curt KU8L Garey Barrell wrote: One other thing as far as Carrier Oscillator crystals. With a little care, you can almost always set the frequency 'better' by ear for best audio, especially since the _CRYSTALS_ inside filters also change, altering the overall shape of the passband slightly. Especially with the Drake where even the BEST adjustment is a compromise. I'd be willing to bet that very few radios would be at their optimum 'sound quality' by setting the CO crystal to a specific frequency, no matter how many places came after the decimal point! :-) 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line and TR-4/C Service Supplement CDs www.k4oah.com Jim Shorney wrote: On Sat, 17 Sep 2011 10:10:53 -0400, Eddy Swynar wrote: What can REALLY be vexing, though, is when the crystal(s) used in carrier-generating oscillator frequencies migrate: I once had an SB-102 transceiver that sounded very tinny nasal-sounding on LSB only---much to my chagrin, THAT carrier generating crystal had shifted just enough so as to put a goodly portion of my signal REMOVED from the passband of the IF filter! I always wondered why some manufacturers didn't put adjustment trimmers in the carrier oscillator curcuit. This is one of the most critical adjustments in a SSB radio, and I'm a-r enough about it these days that I check my frequency counter agianst a rubidium standard before I make adjustments. I actually added trimmer caps to the HW-101 that I had years ago so I could get it right. ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
[Drakelist] Changing crystal frequency
Someone I know used to write on crystals with a pencil claiming the frequency could be changed. Is this true or an urban legend, because graphite is crystalline? ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Changing crystal frequency
- Original Message - From: Neil M Califano cchange...@yahoo.com To: Drakelist@zerobeat.net Sent: Friday, September 16, 2011 5:05 PM Subject: [Drakelist] Changing crystal frequency Someone I know used to write on crystals with a pencil claiming the frequency could be changed. Is this true or an urban legend, because graphite is crystalline? Its true but not because pencil is graphite. A crystal is a mechanical oscillator! The frequency is determined by the mass and thickeness of the crystal along with the cut. Crystals are cut from large crystals which are grown. the angle at which the crystal is sliced in relation to its axis determines the mode of oscillation and many other properties including temperature coefficient. The nature of piezeo electric materials is that they generate a voltage when deformed and will deform if subjected to a voltage difference across the appropriate face of the crystal. Anything on the surface will influence the resonant frequency including the any dirt. Old time crystals were simply blocks of crystal cut to the right angle and placed loosely between two electrodes. They could be varied in frequency a little by the pressure of the electrodes and some crystal holders were made with an adjustment to get a short range of frequencies. Crystals can also be varied by abrasive treatment or adding something to the surface to increase the mass. A pencil mark does this. In the days when crystals were quite expensive there were a lot of articals in ham magazines about how to make your own. After WW-2, when lots of crystals became available surplus, there were numerous articles on how to convert military crystals to ham frequencies and kits with the necessary abrasives were sold. Modern crystals are usually grown and are made with cuts not known sixty years ago. For instance, its possible to make a crystal with zero temperature coefficient over a very wide range. I have not done a web search for piezio electric crystals but I am sure there must be a decent tutorial on them. There was some controversey about just who originated the use of crystals for control of oscillators but the two most likely were A. M. Nicholson and W.G.Cady, the latter of Bell Labs. I think Cady got the patent but Nicholson was probably actually first. Cady's application give much more detail on how to make an actual oscillator, that is probably why he was recognized as the inventor. -- Richard Knoppow Los Angeles WB6KBL dickb...@ix.netcom.com ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Changing crystal frequency
- Original Message - From: Richard Knoppow 1oldle...@ix.netcom.com To: Neil M Califano cchange...@yahoo.com; Drakelist@zerobeat.net Sent: Friday, September 16, 2011 7:32 PM Subject: Re: [Drakelist] Changing crystal frequency Did this myself in 1960, and it works. The added mass will lower the frequency a little, more scribble lowered the frequency more. There is an OP out in Eureka that grinds old FT243 crystals to bring the lower frequency ones up to the desired ham band frequency. The products he sells work FB for boatanchors like my old Globe Scout. That rig has a high crystal current so the fake metalcan crystal in an FT243 case won't cut the mustard. Choip de choip de ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Changing crystal frequency
The older (FT-243 style) crystals could be opened with just three small screws. The rectangular piece of quartz could be removed and cleaned, -OR-, you could make marks on it with a pencil to LOWER the frequency a very small amount. Essentially you were just adding a little mass to the vibrating quartz, slowing it down slightly. Had nothing to do with the composition of the pencil, just added mass. The risk was if you added too much mass, the crystal would get sluggish and even quit oscillating. Then it was time to open it up again and clean off all the pencil marks. 73, Garey - K4OAH Glen Allen, VA Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line and TR-4/C Service Supplement CDs www.k4oah.com Neil M Califano wrote: Someone I know used to write on crystals with a pencil claiming the frequency could be changed. Is this true or an urban legend, because graphite is crystalline? ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
Re: [Drakelist] Changing crystal frequency
Rubbing solder on instead of graphite works a little better as the lead has more mass then graphite. Thus, the oscillations are slightly less and the lead can lower the frequency slightly more then graphite. Lee Bahr, w0vt -Original Message- From: Neil M Califano Sent: Friday, September 16, 2011 7:05 PM To: Drakelist@zerobeat.net Subject: [Drakelist] Changing crystal frequency Someone I know used to write on crystals with a pencil claiming the frequency could be changed. Is this true or an urban legend, because graphite is crystalline? ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist ___ Drakelist mailing list Drakelist@zerobeat.net http://mailman.zerobeat.net/mailman/listinfo/drakelist
