ATTEN AT5011 spectrum analyser

[simonjp]

Hi folks.

I can't think of any other place to turn having sent countless emails to Atten in china and their distributorship in EU without any response.

So I am just clutching straws that someone out there may have a circuit or some guidance on a repair .

I appreciate that the Atten is very basic and not a great deal of use excepting for a quick "look see" in measurements.

This basket case analyser that I got, firstly the frequency display was showing meaningless numbers. I had some historic info that a repair had been attempted in the past and it was around the last mimic before the attenuator on the input.

Sure enough I found that not only was the mimic amp fitted the wrong type, but also around the wrong way! I replace it with the correct type and immediately the frequency display seems to show meaningful values.

I set the analyser aside having convinced myself that I had more than likely fixed the fault. Mistake, this was just the tip of the ice burg.

Returning to it once more, I discover that it is still deaf, and I am really struggling now without the correct circuit diagram.

I suspect the first mixer, but the only available circuit I have got is for the Hameg HM5011, whilst it appears 99% the same, the mixer is not.

The Hameg circuit details the mixer as a mini circuit SYM-3107, I have spoken with Mini Circuits and they have managed to find some old stock, but at the same time have said that the mixer is encapsulated.


The mixer that is fitted in the Atten, is surface mount, but open cased design, if that makes sense.. On what looks like the tiny laminate material is a minute coil and a semi transparent blob, which I can only assume contains diodes.


So can anyone help with the identity of the mixer in the Atten, or suggest to use the SYM-3107 as used in the Hameg.


Lastly I have found more problems, now in the tracking generator. One of the attenuators was destroyed and the final mimic amp ERA-4SM.
I have a replacement amp on its way from mini circuits. I dont have a 1 ghz generator to test the input mixer, so I am hoping that when I have fixed the TG ( currently very low level), that I will be able to set the TG with zero span and use the TG output to input back into the SA and see if the first mixer is doing the business.


However I do fear that and especially judging by the amount of faults relative to both input and output that the last operator may have been aligning a filter and accidentally transmitted into it, destroying components in both halves of the analyser.


Can anyone assist with a schematic please.


Simon

[CJay]

Ah, you found us, welcome

As you're UK, I may be able to help with a sig gen, I'm just outside Manchester so if you're local to me we may be able to sort something out.

You could also use one of the cellphone VCO modules that crop up on eBay from time to time if you need a cheap UHF/GHz signal source and have a frequency counter.

[Fraser]

Th Hameg and the Atten SA's come from the same factory.

The Hameg mixer should work fine in the Attention but, as you say, you will need to make modifications to fit the Encased part that Mini Circuits have found for you.

As you likely know, an SA is just a superheterodyne receiver in many ways. Fault tracing usually requires a signal of known level to be injected into the input and the tracing of that signal through each subsequent stage to determine whether the stage produces gain or loss in signal level. A signal level loss of the type you describe is normally pretty easy to spot on the input stages of an SA. You do need the right test kit to do such however. Any friendly radio amateurs or techs local to you who can help with test kit ? Where in the UK are you located ?

The mixers in these 'simple' SA's are not normally very sophisticated and a replacement is normally relatively easy to find. Please can you post pictures of your suspect mixer. Can you also post the section of the Hameg schematic that covers the RF front end and mixer. I can then see what is likely to have failed and potential replacement mixer options.

Fraser

[Fraser]

I just found the Hameg 5011 service manual.

The good news is that this is one simple Spectrum Analyser !

It should be very simple to graft the Hameg IC3 Mixer into your Atten if that has failed. If the MMIC that follows the Mixer has failed due to overload, it is a pretty safe bet that the mixer got fried as well. the Mixer is a 3 pin device so should be relatively simple to adapt to your Atten PCB. Please provide a photo of the Atten PCB around the mixer.

The LO output driver to the mixer (Hameg IC5) may also have been damaged if a major overload of the mixer occurred.

You are fortunate that these SA's appear to be simple and designed to be repairable. Do not talk down these units. I own several very good SA's but would happily use a Hameg or Atten 5011. Good basic design and performance. I would happily buy one at the right price.

Fraser

[simonjp]

Hi guys an thanks for the help.

Its a bit more than a vintage valve radio to me so its going to be really testing!

I am at home right now, but will try and get some photos of the mixer when I get to work in the morning. Unfortunately I only get 30mins lunch and thats not a great deal of time to eat and fault find.

I am based in hailsham east sussex, but work in lewes.

[sisyphuskühlung]

Hello together,
i got a hameg hm5012 from the dumpster and I need to replace the defective frontend mixer SYM-3107A. I asked minicircuits and they said I have to buy at least 100 of them. So I asked for the datasheet and they said "This model was developed as a proprietary part; unfortunately it is not available for general purchase and we are unable to share any datasheet for this model".

So can you help me finding a replacement, maybe you have a datasheet and Im also looking for the old Software SW5012 (not as100e!).

Greetings S.