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Crystals for A-L Lite

D

dbdigital

Guest
Does anyone know a source for crystals for Chris Cuff's Alfredo-Lite? I need to change the channel on mine to 1620.
I've tried contacting Chris by e-mail but without success. Thanks.

db
 
As I recall Chris had a couple versions of this transmitter. One used a discrete crystal and the other had a clock oscillator (14 pin DIP package in a metal can that plugs in) which is the type I have. Do you have the DIP package version?? If you do, I'll do some checking and find out where I got some additional clock oscillators that are different frequencies (I think it was from Digi-Key). I believe the "can oscillator" operates at 4 times the desired output as there is a divider chip on the front end of the transmitter with that version. Again, I need to do a little checking on this.

What frequency are you currently operating at?? I ask that as I went from 1390 to 1670 and had an issue with much less output. I contacted Chris and he sent me some different inductors for the filter network. I note that you want to go to 1620. If you are already close to that frequency you may not need to change out the inductors.

Regards
 
RememberWHEN said:
As I recall Chris had a couple versions of this transmitter. One used a discrete crystal and the other had a clock oscillator (14 pin DIP package in a metal can that plugs in) which is the type I have. Do you have the DIP package version?? If you do, I'll do some checking and find out where I got some additional clock oscillators that are different frequencies (I think it was from Digi-Key). I believe the "can oscillator" operates at 4 times the desired output as there is a divider chip on the front end of the transmitter with that version. Again, I need to do a little checking on this.

What frequency are you currently operating at?? I ask that as I went from 1390 to 1670 and had an issue with much less output. I contacted Chris and he sent me some different inductors for the filter network. I note that you want to go to 1620. If you are already close to that frequency you may not need to change out the inductors.

Regards
Click to expand...

Many thanks for replying. I have an oscillator at 1610. The TX itself has a 4-pin socket and can use either the oscillator or a standard 2-pin crystal. Any direction you can point me to on this would be much appreciated.

Thanks again.

db
 
Sorry for the delay in responding. First off, I was incorrect in saying that the Cuff transmitter I have has a 14 pin DIP oscillator. I don't think he ever had one like that! It is the 8 pin DIP type (metal can) which is basically square in shape. Looks like I purchased some oscillators from Digi-Key Corporation (800-344-4539) to change the operating frequency. Digi-Key part number is ECS-P85-B-ND. Again, this is in a metal can. Form factor is like a 8 pin mini DIP integrated circuit but there are only 4 pins coming out of the can. Is this what you have??

If so, you will need to tell the representative at Digi-Key that you need the oscillator programmed to 6.4800 Megahertz (the transmitter divides this by 4 equaling your desired 1.620 Megahertz {1620 Kilohertz}). Since this is a specially ordered part it is non-returnable.

Like ICs, this is "polarized" part and needs to be plugged into the socket on the transmitter in a specific way. The metal can on the part is not marked well. Three "edges" on the can are rounded and the forth is square. The pin near the square edge represents pin 1. Hope this helps.

For best performance, once you have changed out the oscillator, wrap the transmitter in a sock puppet. lol

Regards and Merry Christmas to you.

RememberWHEN
 
RememberWHEN said:
Sorry for the delay in responding. First off, I was incorrect in saying that the Cuff transmitter I have has a 14 pin DIP oscillator. I don't think he ever had one like that! It is the 8 pin DIP type (metal can) which is basically square in shape. Looks like I purchased some oscillators from Digi-Key Corporation (800-344-4539) to change the operating frequency. Digi-Key part number is ECS-P85-B-ND. Again, this is in a metal can. Form factor is like a 8 pin mini DIP integrated circuit but there are only 4 pins coming out of the can. Is this what you have??

If so, you will need to tell the representative at Digi-Key that you need the oscillator programmed to 6.4800 Megahertz (the transmitter divides this by 4 equaling your desired 1.620 Megahertz {1620 Kilohertz}). Since this is a specially ordered part it is non-returnable.

Like ICs, this is "polarized" part and needs to be plugged into the socket on the transmitter in a specific way. The metal can on the part is not marked well. Three "edges" on the can are rounded and the forth is square. The pin near the square edge represents pin 1. Hope this helps.

For best performance, once you have changed out the oscillator, wrap the transmitter in a sock puppet. lol

Regards and Merry Christmas to you.

RememberWHEN
Click to expand...

Thanks, R-WHEN. I'll give them a shout. I get the impression that Chris is laying low (like, well below the radar) in light of the FCC action against transmitter builders.

db
 
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