Delay line? Are they still in use?

[romhunter]

The title say it all. I happened to get ahold of a full tube (digital delay line) and wonder if they're still in use? Or widely use?

[helius]

The salad days of delay line chips may be in the past, when they were used for applications as diverse as PAL television decoding and oscilloscope trigger circuits. The most common use these days may be in cheap effects pedals, where they can be used to build reverb and chorus circuits.

[NiHaoMike]

Got the datasheet? That should give ideas on what it can be used for.

[Alex Eisenhut]

They still make em.
https://www.digikey.ca/product-detail/en/texas-instruments/SN74LS31D/296-33992-5-ND/1590557

But there's also the other style that is a hex inverter with a bunch of LC delays between the elements built into a capsule over the DIP14. They are usually tapped along the way.

[wraper]

They still make em.
https://www.digikey.ca/product-detail/en/texas-instruments/SN74LS31D/296-33992-5-ND/1590557

But there's also the other style that is a hex inverter with a bunch of LC delays between the elements built into a capsule over the DIP14. They are usually tapped along the way.

It's not a delay line. Basically just a buffer offering a little bit more delay than most of this TTL series. Delay line is for example TDA4665.

[romhunter]

Here's something I found on a "parts board" few days ago, which give rise to this question:

http://www.alldatasheet.com/datasheet-pdf/pdf/136508/DATADELAY/DLO32F-30MD1.html

Full name is DDU66F, this is something similar.

I got a very vague idea why they use them though. Can someone enlighten me on this matter?

[NiHaoMike]

They're for fine tuning clock phase back when discrete logic was in common use.

[jmelson]

The title say it all. I happened to get ahold of a full tube (digital delay line) and wonder if they're still in use? Or widely use?

The "digital" delay lines are used much less today as many ICs have various timing adjustment functions built in.  They were often used in the past to align timing between various components so that data was clocked in at the best time.  This is very rarely needed today, with FPGAs and such having far more sophisticated mechanisms.  The digital delay lines have buffer-driver circuits after the passive delay line, integrated into the package.

However, the passive delay lines can be used to delay analog signals in many signal processing systems.
We use them in nuclear signal acquisition system to delay linear signals so that a "discriminator' has time to detect the arrival of the signal pulse and start/synchronize the acquisition.

Jon

[trevatxtal]

So Modern!,
The delay lines I worked on in the 70s consisted of a steel spring with a magnetic coupling at either end one could slide along the spring to get accurate delay.
The capacity was 64 bits not bytes and most of the faults were with the driver and receiver
 amps.
Banks of hundreds in large 19inch cabinets supporting memory cards of fer-rite beads woven with miles of fine wire.
All for input to a IBM 360
Bump a cabinet and 32 terminals would go down in the sales department.
You can estimate my age.
Trev

[German_EE]

Age? Somewhere between seventy and eighty. I started work in 1975 when they were still using punch cards and paper tape and I'm now 62.

As for modern uses of delay lines, I used one about six months ago. I had a 45 MHz signal that I needed to delay by a quarter of a cycle (5.55nS) to generate a quadrature signal and a delay line did the job perfectly.