Thanks for another great instructional, Peter. There is nothing like them for sheer ease of understanding and radio fun. Keep up the good work. And see you at Rosebud on Sunday Nov. 18th for our annual RadioFest mate, Cheers Mark B. VK3PDG
Old video, but this is interesting as the aussie East Coast call / net frequency is 7025. Fists is 7028 and often after contact is made on 7025, they’ll drop down to 7020 to rag chew So a reliable swing from below 7020 to 7028 is neat Aussie Parks guys often are on 7032 which is just outside, however there is supply of 7030 and 7020 HC49U crystals from Mouser. I think that might be worthwhile experimenting with.
Peter, do you know why all those Chinese Pixies are at 7.023 MHz? Why that frequency? Is it some sort of mass produced crystal used in consumer products?
Not sure. I've not been aware of that crystal before the Pixie came out. But if they were smart they'd put it a few kHz higher so that American generals & techs can use it.
Yet the 80m super VXO based on colour burst crystals pulled over a far greater range... 80khz if I remember correctly. I wonder if this is to do with the type of 'cut' that is used in the crystal manufacture.
I have not seen that VXO experiment DazzW but I am gueessing with a 95 percent chance those were HC49-U full height ie 14mm height xtals. Internally they are a disc with two off gold plated semi C electrodes. These vibrate in a drum mode. The short ultra cheap xtals are rectangular and vibrate in Beam mode I am not surprised they don not pull well . Generally full height xtals will do +600 and -200 Hz per Megahertz on fundamental as a simple vxo so a 4Mhz nominal should be expected to do + 2400 kHz and perhaps 1.4 x that as two crystal osc. BTW if a silver plated quartz xtal holder is not hermetic an air leaks in then the frequency drops as the xtal gets microscopically heavier via silver oxide. HOw someone got 80 Khz on a 3.59 Mhz VXO is beyond me . I will try to find the video. Be aware that Peter does not heat the whole gubbins up by 15 degrees or so.. therein lies the test !!
Timothy Fidler Hi Tim, yea its here on Peter's youtube channel. It's a much older video where he's got an 80m vxo pulling 80khz. I searched super vxo and it came up as one of the search results. You are right though, that's a darn lot to budge a crystal oscillator. What you were saying with relation to the crystals mode of operation is interesting. I wonder if those really large colour burst crystals you used to find in old teles pull even better.
Peter, you do all of amateur radio a service by expressing (in video form) your curiosity and experimentation. Thank you for another great video.
Thanks for another great instructional, Peter. There is nothing like them for sheer ease of understanding and radio fun. Keep up the good work. And see you at Rosebud on Sunday Nov. 18th for our annual RadioFest mate, Cheers Mark B. VK3PDG
Old video, but this is interesting as the aussie East Coast call / net frequency is 7025. Fists is 7028 and often after contact is made on 7025, they’ll drop down to 7020 to rag chew
So a reliable swing from below 7020 to 7028 is neat
Aussie Parks guys often are on 7032 which is just outside, however there is supply of 7030 and 7020 HC49U crystals from Mouser. I think that might be worthwhile experimenting with.
Right lovely! Thanks for sharing your results with us!
Bonjour! Merci pour cette vidéo.73 qro F5NDL
Hello tanks for the vidéo. Best 73 F5NDL
Hello friend, is there a Portuguese version of the Minimum QRP book?
thanks, Peter! what's the range of your tuning cap you're using here?
I had tried ceramic resonator long time back. They pull much better
7.023 is China CW frequency
Peter, do you know why all those Chinese Pixies are at 7.023 MHz? Why that frequency? Is it some sort of mass produced crystal used in consumer products?
Not sure. I've not been aware of that crystal before the Pixie came out. But if they were smart they'd put it a few kHz higher so that American generals & techs can use it.
7.023MHz is on China ham law
7.023 is the QRP freq in the PRC.
Yet the 80m super VXO based on colour burst crystals pulled over a far greater range... 80khz if I remember correctly. I wonder if this is to do with the type of 'cut' that is used in the crystal manufacture.
I have not seen that VXO experiment DazzW but I am gueessing with a 95 percent chance those were HC49-U full height ie 14mm height xtals. Internally they are a disc with two off gold plated semi C electrodes. These vibrate in a drum mode. The short ultra cheap xtals are rectangular and vibrate in Beam mode I am not surprised they don not pull well . Generally full height xtals will do +600 and -200 Hz per Megahertz on fundamental as a simple vxo so a 4Mhz nominal should be expected to do + 2400 kHz and perhaps 1.4 x that as two crystal osc. BTW if a silver plated quartz xtal holder is not hermetic an air leaks in then the frequency drops as the xtal gets microscopically heavier via silver oxide. HOw someone got 80 Khz on a 3.59 Mhz VXO is beyond me . I will try to find the video. Be aware that Peter does not heat the whole gubbins up by 15 degrees or so.. therein lies the test !!
Timothy Fidler Hi Tim, yea its here on Peter's youtube channel. It's a much older video where he's got an 80m vxo pulling 80khz. I searched super vxo and it came up as one of the search results. You are right though, that's a darn lot to budge a crystal oscillator. What you were saying with relation to the crystals mode of operation is interesting. I wonder if those really large colour burst crystals you used to find in old teles pull even better.
👏👏👏😊