FFT analyzer recommendations

maybe one of the plugs is in the inverted direction? It would look 1:1 but it isn't. check the pin NUMBERS. Gerhard

ote:

t im supprised as to why it doesnt work. just to be sure, can you see if its pin 1 on 1, etc? as i cannot see the whole cable on your image.

could be wrong.

I'Ve tried it both ways, straight and reversed, both with similar results, odd thing beeing if i connect the cable straight, pin number to pin numbe r and omit pin 1-6-9, i dont get the fault at start up, but i get the fault as soon as the controller unit attempts to communicate with the RF unit. ive seen a serial test protocol in the service manual, i guess that's the next stop, and some nice AMP sub-D connectors would be good also.

Gotta say, you guys have a nice online community here, everyone's very help ful, Thank you all! i really appreciate that!

On a sunny day (Tue, 25 Jun 2019 18:45:09 -0700 (PDT)) it happened snipped-for-privacy@personalrecharge.com wrote in :

To see what the situation is, use a voltmeter on pin 2 and 3 of the things, the Tx pin should be negative several volts, and the Rx pin should be around zero volts. Meaure it on both sides, then you know what Rx and Tx is, and cross connect those: Rx to TX on the other sde, and Tx or Rx on the other side. All other ways are guesswork.

Check baudrate and parity settings.

I don't think you have any control over the settings and baud rate.

About the pin numbering - I checked that too. They match.

On a sunny day (Wed, 26 Jun 2019 00:00:48 -0700 (PDT)) it happened Castorp wrote in :

The same goes for the hardware handshake lines, it is not often used these days I think, but it is posssible older equipment uses DTR (data terminal ready, output) on pin 4 and DSR (data set ready, input) on pin 6, same for RTS (request to send, output) on pin 7, and CTS (clear to send, input) on pin 8.

And there is also DCD (data carrier detect, input) on pin 1.

So you cannot connect the cable 1 to 1.

RTS (out) should go to CTS (in), and CTS (in) to RTS (out).

And DTR (out) shoudl go to DSR (in), and DSR (in) to DTR(out)

Or this (with 2 and 3 swapped):

So you can loop back too, ig no handshake is needed by connecting CTS to RTS on the same connector, and DTR to DSR, etc.

Hopefully this does not create more confusion ;-)

It is simple actually.

Just make sure you buy one with the 14 bit IF card...

Care to elaborate?

Cheers

Phil Hobbs

If HP could complicate things, it did.

Possibly company policy to ensure customers captivity.

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Allright then, did some trouble shooting and found that the power supply of the RF unit had a shorted tantalum capacitor, and no negative voltages pre sent, so i replaced the capacitors, and now it communicates, and the voltag es on the power supply seem to be within range. However, now i get a cali bration error on the device, so that's the next puzzle to solve.

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of the RF unit had a shorted tantalum capacitor, and no negative voltages p resent, so i replaced the capacitors, and now it communicates, and the volt ages on the power supply seem to be within range. However, now i get a ca libration error on the device, so that's the next puzzle to solve.

Good job! Do you have Source connected to IN on the RF unit with a short BNC-BNC cabl e?

Well, I don't suppose it'll affect working at baseband since these cards have their own ADC's, but for working at higher frequencies the 14 bit IF card is worth having. Last time I was looking for an E4406 on ebay none of the dozen or so units had the 14 bit IF card.

FYI these are the serial numbers to look out for:-

Serial number beginning MY (made in Malaysia), or US41513009 or greater.

Alternatively, a serial number on this list: US4136 prefix, with suffix

2964, 2977, 2982, 2986, 2987, 2988, 2989, 2990, 2991, 2992, 2993, 2998, 3000, 3003, 3004, 3005, 3006, or 3007.

I have this scope on my bench and I like the FFT function. Off the top of my head, I think it meets your specs...( my scope is fully loaded with all the math packs)

They have been in the market for 4-5 years now so you might be able to pick up a used one at 1/2 price...

Scopes are almost always 8 bits, which limits their FFTs to about 50 dB dyn amic range. (I have four scopes that do FFTs.)

The HP 89410A suits me very well apart from the 1/f noise.

Cheers

Phil Hobbs

It's big and bulky, and awkward. HP made elegant portable FFT-based audio analyzers, to 50 or 100kHz, in the old days. Why can't somebody make similar now, but to 5 or 10MHz?

--
 Thanks, 
    - Win

Well, so am I, except for awkward. I have this nice 7-foot HP rack to put boat anchors in. I pay about three cents on the dollar for top-of-the-line instruments, which suits me very well.

Of course in my line of work, I get to keep the money I don't spend. ;)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs 
Principal Consultant 
ElectroOptical Innovations LLC / Hobbs ElectroOptics 
Optics, Electro-optics, Photonics, Analog Electronics 
Briarcliff Manor NY 10510 

http://electrooptical.net 
http://hobbs-eo.com