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
Quite a few crystal oscillators in a receiver are running on the third-harmonic of the crystal's fundamental frequency. The local oscillator in consumer scanning receivers was calculated with this formula:
* Receive frequency - 10.7 MHz / 3 = crystal frequency
The formula generated a local oscillator frequency that was the first IF frequency (10.7 MHz) after the mixer stage.
On 11/6/2022 12:33 PM, 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
Andy, In times past you could order a suitable crystal from International Crystals in Oklahoma. Unfortunately, due to the proliferation of frequency synthesizers, they are no longer in business. There was another provider of custom crystals in Ft Myers Florida but they are out of business for the same reason. I have ordered custom crystals from both of these manufacturers several times. Another way to generate the exact frequency, for experiential purposes, is you could purchase one of several relatively cheap units to generate the desired frequency. Circuit boards using the ASF4351 synthesizer chip are available on E-Bay for about $40.00. Unfortunately, these require an external programmer to set up. A complete unit with programmer included is about $150.00. Hopefully, this will be a good starting point for you.
-----Original Message----- From: JoAnne Maenpaa [email protected] To: [email protected] Sent: Sun, Nov 6, 2022 3:28 pm Subject: [AMSAT-BB] Re: Crystals for 2m
Quite a few crystal oscillators in a receiver are running on the third-harmonic of the crystal's fundamental frequency. The local oscillator in consumer scanning receivers was calculated with this formula:
- Receive frequency - 10.7 MHz / 3 = crystal frequency
The formula generated a local oscillator frequency that was the first IF frequency (10.7 MHz) after the mixer stage.
On 11/6/2022 12:33 PM, 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
-- 73 de JoAnne K9JKM [email protected] BM DMR TG 98006 -----------------------------------------------------------
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Hi. If it's for a filter, then this is not going to help. However, if it's for a local oscillator source, then I can suggest an alternative is a CMOS version of the Silicon Labs Si590. (Digikey) They are very reliable, have low phase jitter and although they are around 200 Ohms output impedance, if you need 50 ohms, for example a ring mixer, then you can follow it with a 4:1 transformer. Regards David G0MRF
-----Original Message----- From: Andy Brian [email protected] To: AMSAT-BB [email protected] Sent: Sun, 6 Nov 2022 18:33 Subject: [AMSAT-BB] Crystals for 2m
Hi, I'm looking for good source of crystals between 156.5 and 156.600MHz for build experimentallinear transponder. Please for any got information or some other solutions.I received a few from marine scanners but it seems not 156Mhz BR Andy -----------------------------------------------------------
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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/[email protected] 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
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 [email protected] 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/[email protected] 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/[email protected] 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
Typically an NE612 front end needs about 50mV of local oscillator. So, one transistor osc followd by a second transistor buffer/limiter can feed a two or three section bandpass filter to directly drive the ne612. Your entire front end could run on less than 5mA of current at 6v.
On Mon, Nov 7, 2022, 7:51 AM Ashhar Farhan [email protected] wrote:
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 < [email protected]> 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/[email protected] 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/[email protected] 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
participants (6)
-
Andy Brian -
Ashhar Farhan -
David G0MRF -
JoAnne Maenpaa -
w4tas＠gte.net -
Wendy and Terry Osborne