DIY Intersil Phase Meter

Hello all,

I am generally new to DIY projects but am looking to build the Intersil/Harris phase meter detailed in the attached PDF.

However, Intersil no longer sells the ICs noted in the schematic. Can anyone tell me some alternatives to these chips that I could use in my project? I need to use through hole mounted devices. Any help would be greatly appreciated!

Thanks,
Parker

The HA5024 can be found here https://www.ebay.com/itm/2PCS-X-HA5024IP-IC-AMP-VIDEO-125MHZ-QUAD-20DIP-Inte-r/332272049198?epid=20003594019&hash=item4d5cf51c2e:gb4AAOSwwzhZSLbf

The HA5020 is a current feedback video opamp, you can most certainly find a replacement on mouser, I found this one https://www.mouser.com/ds/2/609/1223fb-1270406.pdf

The long tailed pair HFA3102 is a problem, you can  use something like the THAT 300 http://www.thatcorp.com/datashts/THAT_300-Series_Datasheet.pdf and add externally the remaining transistors in the emmiters.

The HA5170 is a JFET input opamp, doesnt look anything special, you can probably use a TL072 or OPA134 here.

That app-note $ELL$ Harris chips.

HA5042 was a cute way to get variable gain; but I have no idea why you "need" it on the *reference* input.

HA3102 may as well be six jellybean NPNs.

The whole dang thing could, for most audio purposes, be a TL072 as two HIGH-gain (clipping) amplifiers and two resistors to mix that to a cap and the voltmeter.

The whole dang thing could, for most audio purposes, be a TL072 as two HIGH-gain (clipping) amplifiers and two resistors to mix that to a cap and the voltmeter.

Click to expand...

Exactly, you can try this instead:
donaupeter.de/audio/Korrelation/Korrelationsgradmesser_schematics.pdf

Here is a pcb-layout for it:

analogguru said:

Exactly, you can try this instead:
donaupeter.de/audio/Korrelation/Korrelationsgradmesser_schematics.pdf

Here is a pcb-layout for it:

Click to expand...

I built this but it is not working properly. I have been troubleshooting for a while and am not sure what's wrong with the circuit. I got the clipping amplifiers and the voltmeter to work but the XORs are throwing me off. What's the point of XORing the same two signals twice and then mixing them? Wouldn't it be the same as just XORing them once? Also, why do you have to XOR Vcc and ground? Wouldn't this just be a constant voltage anyway? Finally, if I'm XORing two signals that are completely in phase (say a simple sine wave), wouldn't the output of the XOR be a 0? This seems like the opposite of what I would want for a phase meter. Maybe I don't really know how the 4070 works.

> What's the point of XORing the same two signals twice and then mixing them?

I don't think that is the idea.

You can't make an XOR as cheap as you can buy the 4-pack '4070.

If you use just one of four, you MUST give the unused gates something to do, or like a dog alone at home, they will get into trouble.

CMOS gates parallel well; CMOS inverters are often used parallel to drive heavy loads.

So since all 4 gates need work, the designer paralleled 2B and 2C as a beefier XOR.

The "out of phase" condition is the high level of the gate, an uncertain voltage. Gates 2A and 2D repeat the BC double-up but with out-phase drive, so we get the true "high" value of gates in this chip. (For light loads the difference "high" or Vcc may be teeny-- this may be over-cute, but "something" had to be done with pins 1 2 12 13.)

I bet it works the same with one active gate, and three gates' inputs tied to ground. But whatever.

For LSP1 LSP4 in-phase, the XOR is low. For LSP1 LSP4 out-phase, the XOR is high. For LSP1 LSP4 at in-between phase, the XOR is in-between.

The LM3914 is ratiometric. You put your low limit at Rlo, high limit at Rhi, and it reads Sig in relative to those voltages. Here gate-Low is approximated with Gnd, gate high is well set by a gate wired high.

A low-pass is desirable so the LEDs don't flicker madly. R7 C4 does this, with some loading on gates 2B 2C, which may have suggested the double-up beefing.

I have _no_ idea what PR1 is for. You can dial it down so no phase-signal gets to the display-- why? The right setting seems to be to dial it 6.8% above the top of the pot, to get the full range. Ah, perhaps the LM3914's top threshold suggests a reduced input. (ah-ah: he's not using all 10 LEDs so indeed the top is 105 shy of Vcc.) Still I see no reason for a large variation.

Okay I got it working with simple sine waves at least. It's definitely finicky though. Any suggestions on making the XOR output more stable/consistent?

Also, I found the bar display to work better using the LM3914 configuration from the 3914 data sheet in the picture attached with the XOR outputs still connected to the same pins. Is there any reason to use the configuration in the schematic over this configuration?

Hello,

Now the LEDs light but they slowly cycle one at a time up all the way up and all the way down as if there’s a step time. I have no clue why this is happening or where the step time would be coming from considering the circuit was working completely fine a few days ago. I am using two equal sine waves as the inputs for the phase meter and as increase the frequency of the sine waves the step time of the LEDs seems to increase as well. Why is this happening and how can I fix it?

Got the IC as SMD sample from Intersil a few years back. Never got down to building the unit (cos very low priority). Willing to part, but you'd have to wait until July/August cos I have those parts stored overseas.