Texar Prism clone prototype Finished Version

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flyboy71
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Re: Texar Prism clone prototype

Post by flyboy71 »

I havent posted any updates on this project for awhile since I've been juggling other projects that took priority. I spent some time on my long weekend to move this to something that I can actually make available. Over the past few months since I first built the prototype, I found that the IC's I used on this design are apparently a victim of the global chip shortage but it appears distributors have plenty on order and a handful in stock. I have some alternatives also that can be used. That being said I pushed along and finished the display and main processor PCBs. I may order these before my vacation since it will take a couple weeks to arrive.

I never really posted the details of this design and how it works. I included some diagrams here:

The overall system:
PrismCloneSystem2.pdf
(21.56 KiB) Downloaded 425 times
Band processor. One per band, 4 total.
PrismCloneProcessor2.pdf
(16 KiB) Downloaded 436 times
The display PCB layout. Two are required for a two channel processor
DisplayPCB.JPG
The 4 band processor PCB layout. Two are required for a two channel processor
BandProcessor.JPG
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mediatechnology
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Re: Texar Prism clone prototype

Post by mediatechnology »

Thanks for the update.
Lots of stuff is on back-order - it's getting pretty crazy.
flyboy71
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Re: Texar Prism clone prototype

Post by flyboy71 »

And so it waits again. I was preparing to order boards and parts and over my vacation two key components with no direct substitutes went from literally thousands to zero in distribution. Expected dates from Mouser are Oct for stock and I am seeing expected dates from June that they cant fulfill. Its like the toilet paper of the semiconductor industry out there. Not re-designing this again for the third time. I will just wait out the chip shortage and pounce when stock is available.
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mediatechnology
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Re: Texar Prism clone prototype

Post by mediatechnology »

I'm seeing long lead times on very basic commodity parts like LM-series regulators, common transistors, Wima caps and film resistors.
I've been having some luck finding out-of-stock Mouser items at Digi-Key recently.

I'm reluctant to suggest it but have you looked on ebay?
I've found some US-based alternate sources for Phoneix connectors there recently.
Someone there may have a stash of ICs you need that hopefully aren't counterfeit.

I remember back in the 80's when this happened and delivery of 74LS-series parts and other gold-doped lines got in very short supply and expensive. 74LS245s were going for several dollars apiece.
flyboy71
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Re: Texar Prism clone prototype

Post by flyboy71 »

I pretty much go to Digikey and Mouser but Ive been all over the map on others looking for parts. Nice thing about Mouser is they give an expected date on inventory. eBay scares me for semis, not so much for connectors and discretes. I was looking there and everything is out of China and I see some price gouging.

I see where Microchip is suffering the brunt of the problem and unfortunately this project uses a PIC to do what it does.
My projects site: https://ornerscorner.neocities.org/

"Things are more like they are now then they ever were before" - Dwight
flyboy71
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Joined: Thu Nov 21, 2019 6:56 am

Re: Texar Prism clone prototype

Post by flyboy71 »

A through hole version of the design is now in the works. The only board that is still SMD is the display board but the display ICs are SOIC which is still reasonable to hand solder, plus there arent alternatives in DIP. Boards and parts are on order and my goal is to have this built and tested in a couple weeks and then if it works as the original I will write a build guide and parts lists, schematics, assembled boards, etc.
Attachments
DS1.pdf
Display board schematic
(91.16 KiB) Downloaded 408 times
BP1 SCH.pdf
Main processor schematic
(116.46 KiB) Downloaded 406 times
Display PCB
Display PCB
Main 4 band processor board
Main 4 band processor board
My projects site: https://ornerscorner.neocities.org/

"Things are more like they are now then they ever were before" - Dwight
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mediatechnology
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Re: Texar Prism clone prototype

Post by mediatechnology »

Thanks for moving to through hole.
I'm glad you could find inventory in TH.

People are always saying "Why don't you use SMT?" and I counter with "Would you be willing to support the builders who can barely solder through hole to help them clean up their SMT mess?"
It's easy for people to say stuff without thinking through the consequences.

If you do sell a kit you might consider selling the display board with the SMT parts pre-soldered.
I've seen some ham gear that way.
flyboy71
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Re: Texar Prism clone prototype

Post by flyboy71 »

I plan to offer the display boards with the SMD parts assembled as well as the PIC chips pre-programmed. Everything should be just wire and go. Once I have my rack mount enclosure I will assemble this into a real project and create my FPE design file.

I need to spin up the input/output circuit yet which is just getting balanced signals in and out. Ill order some THAT1206 and 1646 parts and breadboard it to this design and try it out. Maybe the stereo width controller would be a nice addition on the front end.
My projects site: https://ornerscorner.neocities.org/

"Things are more like they are now then they ever were before" - Dwight
flyboy71
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Joined: Thu Nov 21, 2019 6:56 am

Re: Texar Prism clone prototype

Post by flyboy71 »

Boards arrived today. Most of the parts are here, just waiting on one item yet in a shipment from Mouser due tomorrow. I hope to have this up and running and checked out this weekend.
Attachments
20210812_165747_resized (1).jpg
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mediatechnology
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Re: Texar Prism clone prototype

Post by mediatechnology »

Good news!
Glad you (almost) got all the parts.
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