R2670A RF I/O not working

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radiocat37
Posts: 210
Joined: Mon Sep 22, 2003 9:59 am

R2670A RF I/O not working

Post by radiocat37 »

I have an R2760A that passes all calibration tests and both the ANT port and the Gen out port are fine. Does the RF I/O port have a fuse like the others? No signal comes out of the RF I/O port and no signal goes into the port; at least not showing on the screen. Every other function seems to work just fine. Analyzer is very clean and is well cared for.

Any help and/or advice appreciated. I do have another analyzer (R2600B) to assist with diagnosing.
Brian Griffin: Ah, if my memory serves me, this is the physics department.
Chris Griffin: That would explain all the gravity.
.

Lois: Peter, you're drunk again.
Peter: No, I'm just exhausted because I've been up all night drinking.
radiocat37
Posts: 210
Joined: Mon Sep 22, 2003 9:59 am

Re: R2670A RF I/O not working

Post by radiocat37 »

A follow up. I looked through some posts and am going to remove the bottom and see if the center pin connection is intact; also ohm it out and check that.
Brian Griffin: Ah, if my memory serves me, this is the physics department.
Chris Griffin: That would explain all the gravity.
.

Lois: Peter, you're drunk again.
Peter: No, I'm just exhausted because I've been up all night drinking.
jry
Posts: 481
Joined: Fri Feb 06, 2004 3:14 pm

Re: R2670A RF I/O not working

Post by jry »

you can just measure at the N connector ...should see 50 ohms.

sometimes its the connection but more often the attenuator is blown/failed.
radiocat37
Posts: 210
Joined: Mon Sep 22, 2003 9:59 am

Re: R2670A RF I/O not working

Post by radiocat37 »

I do have 50 ohms at the N-connector. As far as the attenuator, what does that entail to fix? And if doable are parts readily available?
Brian Griffin: Ah, if my memory serves me, this is the physics department.
Chris Griffin: That would explain all the gravity.
.

Lois: Peter, you're drunk again.
Peter: No, I'm just exhausted because I've been up all night drinking.
jry
Posts: 481
Joined: Fri Feb 06, 2004 3:14 pm

Re: R2670A RF I/O not working

Post by jry »

I would look internally then on the RF I/O wattmeter module.

Measure the resistance at the input attenuator output. ( PCB side as opposed to the N connector ) That should be lower ...around 25-30 ohms IIRC. If you get something else CAREFULLY lift the tab from the PCB and that should measure 50 ohms.

If you are lucky it's not the input attenuator and just something further back. The part itself is extremely expensive and was calibrated as a unit with the rest of the module at the factory. The replacement parts are very very close so that doesn't throw it off too badly ...spec was +- 5% on the wattemeter anyway.

The input attenuator feeds into another attenuator and I believe the power measurement diode at that point .

Usually when those fail it will read open from the N connector. You may want to inspect the connection ribbon from the N connector to the pad itself for any cracks or breaks just in case it's intermittent.

Even when they fail you will get something on the RF I/O ...will be 20-30 db off but something.

You can PM if you want on repair options.
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