The trouble with using the si5xxx PLLs is that they consume too much power for a cubesat. Typically 30mA. I am assuming you are shooting for a 10.7 MHz IF for 146 MHz RF frequency. If you flip to lower side injection, your local oscillator will now have to be around 135 MHz. This is the fifth multiple of 27 MHz crystal. Getting it to oscillate on the 5th overtone is tricky and unreliable. A better scheme is to use the oscillator at 27 MHz and feed it to a hard limiter that produces rich odd harmonics and filter out 135 MHz. For exact frequecy, you could get away with the CB crystals. - f
On Mon, Nov 7, 2022, 6:52 AM Wendy and Terry Osborne wandtosborne@gmail.com wrote:
Hi Andy,
You could try https://www.hy-q.com.au/ Or https://www.rakon.com/ It's a long time since I bought crystals but I have had good service from both companies. I was going to suggest International Crystals but it seems that they are out of business. Here is a good reference: https://www.everythingrf.com/directory/rf-quartz-crystals
These days, I would suggest using AMSAT's Linear Transponder module (LTM) which is described in the 2022 AMSAT Symposium proceedings. You can access this from the https://launch.amsat.org/ if you are a member.
"The AMSAT Linear Transponder Module" was presented by Burns Fisher, WB1FJ. The LTM is a multi-use transponder board set designed for universities and other partners launching cubesats who have need for a communications component. Similar to the radio systems in Fox and GOLF, the partnership provides easy downlinks for universities and a transponder for amateurs.
Some years ago, I designed a simple analogue linear transponder the prototype is detailed here.
https://www.dropbox.com/scl/fo/ivdkfd19bf68rda2y71ic/h?dl=0&rlkey=e4rng2... It may be of some interest.
73,
Terry Osborne ZL2BAC
On 7/11/2022 7:33 am, Andy Brian wrote:
Hi,
I'm looking for good source of crystals between 156.5 and 156.600MHz for build experimental linear transponder. Please for any got information or some other solutions. I received a few from marine scanners but it seems not 156Mhz
BR Andy
Sent via AMSAT-BB(a)amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership.
Opinions expressed
are solely those of the author, and do not reflect the official views of
AMSAT-NA.
Acceptable Use and Privacy Policies available at
https://www.amsat.org/about-amsat/
View archives of this mailing list at https://mailman.amsat.org/hyperkitty/list/amsat-bb@amsat.org To unsubscribe send an email to amsat-bb-leave(a)amsat.org Manage all of your AMSAT-NA mailing list preferences at
Sent via AMSAT-BB(a)amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Acceptable Use and Privacy Policies available at https://www.amsat.org/about-amsat/
View archives of this mailing list at https://mailman.amsat.org/hyperkitty/list/amsat-bb@amsat.org To unsubscribe send an email to amsat-bb-leave(a)amsat.org Manage all of your AMSAT-NA mailing list preferences at https://mailman.amsat.org