MPP Beach REV-E

[SVEN1]

I managed to upgrade a REV-D MPP to REV-E without damaging any pads or traces. Desoldering components can be a bit of an art (i.e. some swearing is involved).

Its amazing how good you can get desoldering with the sucker pictured below and Asalco braid http://www.asalco.com/products/elect...oldering-braid

https://www.youtube.com/watch?v=iWkPNjvPccY

[Tibuck19]

as opposed to a real de-soldering station like my DS600 ? JS

[Tibuck19]

To replace the 740 with a 840 no need to desolder just cut the 740 legs long and solder .

My board already looks like Frankenstein as it is hahaha.

[Qiaozhi]

MartyJ1963 has successfully completed a REV-E build, but noticed that C20 is listed as 100nf in the parts list instead of 470nF.

I have corrected the Build Document and placed the updated version in the sticky post. If you downloaded the Build Document before the 30th March 2018, then please go and get the new version.

[jinbiao]

Looking forward to MPP Gold

[MartyJ1963]

Hi all,,,I've recently completed my MPP Beach Rev E and I'm wondering if anyone can tell me which IC is the chip that gives the ticking sound? My MPP Rev D ''Ticks'' along nicely, like a little geiger counter, but the Rev E doesn't. It sounds similar to the Surf and Barracuda when first switched on,,,,you can hear a slight Ticking sound but it's high pitched and screechy,,,,,it doesn't affect the detection or sensitivity etc but the sound can get a bit annoying so I thought if I knew which chip creates this I can try a few different ones to see if it will alter. I'm using a fast coil (3dss),,306uh,,,,1.13 ohms. I get a good strong signal on a 1 Euro at about 12" but it hasn't been fully 'Tuned' yet,,,,this is the detection I get at the moment from first time switching on after building. I'm really pleased as it stands at the moment. My MPP Rev D was kindly looked at and repaired by the very kind Silverdog (Andy) so I am really pleased that I completed a working MPP by myself. As you all may tell, I still have a lot to learn so any help on this will br gratefully appreciated. Thanks all. Marty

[Qiaozhi]

MPP REV-E should sound the same as the REV-D version.

Try probing your working REV-D board with a scope and note what the waveforms look like. Then do the same with REV-E. You must have a component in the wrong place or a faulty part. Check the circuitry around U4 and U8.

[MartyJ1963]

Hi Qiaozhi,,,,Thanks for the reply. I will check the places you mentioned. The depth and sensitivity is great,,,about 12" on a 1 euro on a 306uh coil at 1.13 ohms. I've adjusted R5 to 400us,,R14 to 8ms and the minimum sample delay to 10us as per the build file...but my Rev D 'Ticks' really nicely and the Rev E sort of ticks but at a higher pitch and a little 'scratchy',,,it's hard to describe properly. Is the detection range ok at 12" for this kind of coil? I have a lot of spare IC's for this build so shall I change them all and see if there's a difference? Thanks for all the help. Marty

[Tibuck19]

are you testing indoors near a WIFI router by any chance?? I know when I detect around outside near houses when I get near, a router the sound changes dramatically, Interference, like you , I do not lose detection depth but the sound is all screechy

[MartyJ1963]

Hiya Tibuck19,,,,I'm testing it upstairs in a spare room I made into a projects room,,,,my WiFi router is housed downstairs in the living room. I've tested both, earlier this evening, and both sound totally different to each other. The Rev D sounds really nice and clean, like a geiger counter, but the Rev E 'ticks' (in a fashion) and sounds scratchy,,,,they have both been tested one straight after the other so I know they're not picking any interference up. I thought it may be an IC issue,,maybe I ought to swap them all out and re-test? Thanks. Marty

[kt315]

tune the generator sure on 600Hz. 60 x 10.
you have interference.

[6666]

are you testing indoors near a WIFI router by any chance?? I know when I detect around outside near houses when I get near, a router the sound changes dramatically, Interference, like you , I do not lose detection depth but the sound is all screechy

I suffer from bad router EMI in my location, I am surrounded by routers from nearby neighbours, there is a simple test you can do, if you have a laptop with wifi, go to the wifi information section and just have a look at what wifi signals are there.

[MartyJ1963]

Hi KT315,,,Wouldn't the interference be noticed on both detectors though?,,,I am testing both in the same room under the same conditions. The Rev D detector sounds great,evrything is nice and clear sounding,, the Rev E detector sounds different,,it sounds scratchy and doesn't make the 'Ticking' sound like the Rev D. Thanks. Marty

[MartyJ1963]

Thanks 6666,,,I will have a look. Marty

[6666]

The "tick" comes from the last 555.