Does anyone know of a source for 784 MHz crystals?
I'd like to try to 'accurize' the timer in the HP-45 calculator.

-John

John Crane wrote:
---------------------------
Does anyone know of a source for 784 MHz crystals?

** You mean kHz.

I'd like to try to 'accurize' the timer in the HP-45 calculator.


** You need a broken HP-55 to scavenge one from.



...... Phil

On 5/19/21 10:12 PM, Phil Allison wrote:
John Crane wrote:
---------------------------
Does anyone know of a source for 784 MHz crystals?

** You mean kHz.

I'd like to try to 'accurize' the timer in the HP-45 calculator.


** You need a broken HP-55 to scavenge one from.



..... Phil

Yes, that's possible. I have a HP-55 and it works, so I don't want to
cannibalize it. I'm sure there has to be some company that can custom
manufacture crystals to specs. I did try Bomar, but have not received a
reply.

-J

In article ews.com,
says...

Yes, that's possible. I have a HP-55 and it works, so I don't want to
cannibalize it. I'm sure there has to be some company that can custom
manufacture crystals to specs. I did try Bomar, but have not received a
reply.




Many crystal companies that make them for indivuduals have gone out of
business. For the ones that are still in business you can expect to pay
from $ 50 to $ 100 for a one of a kind. Thre is a company in England
that makes crystals to order, but you are still looking at over $ 50
each.

Years ago there were several companies in the US that would make about
any crystal you wanted. Now most radios use one master crystal and from
there use electronics to cover all the frequencies, there is not much
demad for the crystals. Unlike years ago where each radio frequency
required a seperate crystal.

John Crane wrote:
==================
Phil Allison wrote:
John Crane wrote:
---------------------------
Does anyone know of a source for 784 MHz crystals?

** You mean kHz.

I'd like to try to 'accurize' the timer in the HP-45 calculator.


** You need a broken HP-55 to scavenge one from.


Yes, that's possible. I have a HP-55 and it works, so I don't want to
cannibalize it. I'm sure there has to be some company that can custom
manufacture crystals to specs. I did try Bomar, but have not received a
reply.

** If you have done any Googling on this at all, you know that there is no such company.

Stop being such a naive PITA.


...... Phil

In article ,
says...

Yes, that's possible. I have a HP-55 and it works, so I don't want to
cannibalize it. I'm sure there has to be some company that can custom
manufacture crystals to specs. I did try Bomar, but have not received a
reply.

** If you have done any Googling on this at all, you know that there is no such company.

Stop being such a naive PITA.


Do you mean this company :

http://bomarcrystal.com/

Ralph Mowery wrote:

Yes, that's possible. I have a HP-55 and it works, so I don't want to
cannibalize it. I'm sure there has to be some company that can custom
manufacture crystals to specs. I did try Bomar, but have not received a
reply.

** If you have done any Googling on this at all, you know that there is no such company.

Stop being such a naive PITA.

Do you mean this company :

http://bomarcrystal.com/


** FFS they don't make one off specials for hobbiest ******s like the OP.



...... Phil

On Thursday, May 20, 2021 at 8:44:37 AM UTC-7, John Crane wrote:
On 5/19/21 10:12 PM, Phil Allison wrote:
John Crane wrote:
---------------------------
Does anyone know of a source for 784 MHz crystals?

** You mean kHz.

I'd like to try to 'accurize' the timer in the HP-45 calculator.

... I'm sure there has to be some company that can custom
manufacture crystals to specs. I did try Bomar, but have not received a
reply.

There's factory-programmable oscillators that use internal logic to create
custom frequencies, which has better cost and leadtime than custom crystals.

DigiKey will even program it for you...

https://www.digikey.com/en/products/detail/epson/SG-8018CB-TJHSC/7784073

In article ,
says...

There's factory-programmable oscillators that use internal logic to create
custom frequencies, which has better cost and leadtime than custom crystals.

DigiKey will even program it for you...

https://www.digikey.com/en/products/detail/epson/SG-8018CB-TJHSC/7784073



I bought a couple similar to those. Problem is that if you want to put
them very close on frequency like you can with a crystal and trimmer
capacitor you are out of luck.

They only cost a few dollars, under $ 5 if I recall correctly instead of
around $ 50 that Bomar would want for a crystal. They do put out a
waveform roughly equal to a square wave.

On Wed, 19 May 2021 21:12:30 -0500, John Crane
wrote:

Does anyone know of a source for 784 MHz crystals?
I'd like to try to 'accurize' the timer in the HP-45 calculator.

I doubt any go that high.

-John

On 5/19/21 9:12 PM, John Crane wrote:
Does anyone know of a source for 784 MHz crystals?
I'd like to try to 'accurize' the timer in the HP-45 calculator.

-John
Make that kHz.

On 5/19/21 9:12 PM, John Crane wrote:
Does anyone know of a source for 784 MHz crystals?
I'd like to try to 'accurize' the timer in the HP-45 calculator.

-John

Make that kHz.

In article ews.com,
John Crane wrote:
On 5/19/21 9:12 PM, John Crane wrote:
Does anyone know of a source for 784 MHz crystals?
I'd like to try to 'accurize' the timer in the HP-45 calculator.

Make that kHz.

You probably found this link already:

https://davidreaton.com/hp-calculators/hp-45/

I got to that link from the opposite direction, in that I used to modify
video game systems and we'd use custom oscillators in place of crystals in
order to mess with the region or the video output timing. So the timing
circuit that Mr. Reaton uses in place of a 784 kHz crystal works on the
same valid principle.

-KKC, wandering around the abandoned world of Usenet like the Omega Man.
--
-- "People with happy families don't become spies. A bad | kendrick
childhood is the perfect background for covert ops. You | @
don't trust anyone. You're used to getting smacked around, | io-nyc
and you never get homesick." - Michael Westen, /Burn Notice/ | .com