Home made bat detector (1 Viewer)

My husband (electronics engineer) got a design for a bat detector off the internet. He made the box but we can hear every sound going but no bats.
It was an American design does this make a difference.
Has anyone made one that works. Or knows where we can get a circuit diagram from.

Any advice would be welcolm

Ellen

Home built bat box.

willowa said:

It was an American design does this make a difference.

Click to expand...

Ellen,

It shouldn't matter where the design or components came from as long as the box can detect in the range of 18 - 120 kHz it should be able to detect all 16 species of British bat.

I've never built one, although I did think about it. I was put off by the blurb that said it was a difficult build suitable for skilled hands only (like your husband, I guess) and the saving wasn't huge against the price of a fully guaranteed built one, £20 I think.

Any time I've used one or seen one used we were able to see the bats and only used the box to identify species. Not many about at this time of year though.

Alana Ecology do several different ones including one in kit form but no schematic drawing.

They also do a very interesting catalogue of all sorts of equipment for nature lovers/workers/enthusiasts etc.

Derek W

Thank you Derek.

I have never seen a bat box for £20. The ones on the web was £100 plus. I have not seen any bats for a while. They used to roost under the tiles at the front of my house where it gets hot. But looks like they have moved on.

Hi Ellen,

Noticing and reading your thread made me think I could try that. I'm an electronic engineer and I've always wanted a bat detector and also the local parks Friends group which I'm involved in may hold a bat evening later this year.

Which design did your husband get from the internet? I've just browsed and seen this one http://pw1.netcom.com/~t-rex/SBD2.html

If I give it a go I'll let you know if it works.

Gi

willowa said:

He made the box but we can hear every sound going but no bats.
Any advice would be welcome

Click to expand...

Might be stating the obvious here, but it wasn't clear from your post when you were trying to detect bats ...are you tring to detect bats now? Other than perhaps the odd one out for an unseasonal wander, they are all in hibernation and probably blissfully unaware of any detectors, American or otherwise.

willowa said:

They used to roost under the tiles at the front of my house where it gets hot. But looks like they have moved on.

Click to expand...

I'm by no means a bat expert, but I believe that (in general) such sites would be summer roosts only. Winter roosts would be in environments, for example caves and mine shafts, where the temperatures are more likely to stay rather more constant. Hence, if you had bats 'some time ago', I would hazard a guess that you are lucky enough to have a summer roost and perhaps they'll be back with the spring.

If I am wrong, I'm sure someone with more bat expertise will be alone soon.

gi2012 said:

Hi Ellen,

Noticing and reading your thread made me think I could try that. I'm an electronic engineer and I've always wanted a bat detector and also the local parks Friends group which I'm involved in may hold a bat evening later this year.

Which design did your husband get from the internet? I've just browsed and seen this one http://pw1.netcom.com/~t-rex/SBD2.html

If I give it a go I'll let you know if it works.

Gi

Click to expand...

Hi,
I am not sure which circuit design he used. But threre seems to be a design fault. He is going to build a filter into it so only the high frequencey comes through.
Will keep you posted if we pick anything up when the weather warms up .

Jos Stratford said:

I'm by no means a bat expert, but I believe that (in general) such sites would be summer roosts only. Winter roosts would be in environments, for example caves and mine shafts, where the temperatures are more likely to stay rather more constant. Hence, if you had bats 'some time ago', I would hazard a guess that you are lucky enough to have a summer roost and perhaps they'll be back with the spring.

If I am wrong, I'm sure someone with more bat expertise will be alone soon.

Click to expand...

We only tried it in the summer but wanted to know if anyone had tried to make one that worked properly. So we would be ready for summer.

willowa said:

I have never seen a bat box for £20.

Click to expand...

Sorry, that's not what I meant. The difference in price between buying a bat box built and the same model in kit form was £20. I reckoned it was worth the extra £20 to have less hassle and a guarantee. In the end I did neither because one became available to me at work. :t:

Your bats may return to your house. They are known to use different summer and winter roosts

Derek

DJRWhittle said:

Sorry, that's not what I meant. The difference in price between buying a bat box built and the same model in kit form was £20. I reckoned it was worth the extra £20 to have less hassle and a guarantee. In the end I did neither because one became available to me at work. :t:

Your bats may return to your house. They are known to use different summer and winter roosts

Derek

Click to expand...

I noticed, what I thought was mouse droppings on the windowsill. Then it dawned on me that mice could not get the high so must be bats. But have not seen any droppings for about two years so they may have gone.

willowa said:

Hi,
I am not sure which circuit design he used. But threre seems to be a design fault. He is going to build a filter into it so only the high frequencey comes through.
Will keep you posted if we pick anything up when the weather warms up .

Click to expand...

Hi,

Nosing around work, I've found half of the components for the bat detector that I linked to on the previous post. Sorting part numbers to order the rest and hopefully should have it built within a couple of weeks.

Where I work we make audio test equipment and have a signal generator that generates signals up to 40kHz so I'll be able to test it before the bats come out of hibernation.

Gi

gi2012 said:

Hi,

Nosing around work, I've found half of the components for the bat detector that I linked to on the previous post. Sorting part numbers to order the rest and hopefully should have it built within a couple of weeks.

Where I work we make audio test equipment and have a signal generator that generates signals up to 40kHz so I'll be able to test it before the bats come out of hibernation.

Gi

Click to expand...

My husband is into making valve Amps for my sons electric guitar. And radios, he is building a moors receiver at the moment. So he had alot of the components for the bat box already. He also has a signal generator. I will keep you informed.

willowa said:

I noticed, what I thought was mouse droppings on the windowsill. Then it dawned on me that mice could not get the high so must be bats. But have not seen any droppings for about two years so they may have gone.

Click to expand...

A bit late since they've been gone for about two years but if you pick up a bat dropping and rub it between your finger and thumb it will feel dry and easily fall apart into the insect debris it is made up of. :bounce: Mouse droppings on the other hand are more moist and yeuch! :-C

Derek

Finished the home made bat detector today. Tested and works OK by pointed it towards running water, jangling keys and old computer monitor.
:bounce:
May need to fine tune it. Have got parts for another frequency division design although waiting on back order for the transducer. Am looking to do a more complicated heterodyne detector also.

Gi

gi2012 said:

Finished the home made bat detector today. Tested and works OK by pointed it towards running water, jangling keys and old computer monitor.
:bounce:
May need to fine tune it. Have got parts for another frequency division design although waiting on back order for the transducer. Am looking to do a more complicated heterodyne detector also.

Gi

Click to expand...

Let me know when you pick up a bat. I'm not convinced there are any around us. Will have to wait till warmer weather to be sure.

At long last I tried out the bat detector. I organised an evening in the park for bats and moths and from 9.30pm went out and about with sightings of Pipstrelle. I started using the detector and brilliant - lots of clicking as they flew past.

Over the ponds and flying above mature trees, two large bats - Noctule? - with single clicks picked up on the detector.

The second detector I built does not seem to work but I did not use it on the night and at some point may try to build a heterodyne detector.

Gi

Hi, I too have built the Tony Messina bat detector and it's an excellent little tool for the price. If you'd like the benefit of someone else's experience the following parts work well, all from Maplin http://www.maplin.co.uk

Description--------------------------PCB Comp No.-----Maplin P/N-----Price
Plastic Case with 9 volt battery clip-----n/a-------------ZB17T--------£3.29
40KHz Transducer----------------------n/a-------------HY12N--------£4.99
Binary Counter HCF4024BEY------------IC3-------------QX13P--------£0.86
High Impedance Ceramic Earphone------n/a-------------LB25C--------£1.99
10K Ohm PC mount variable Resistor----RV1-------------UH03D--------£0.19
LM386N-1Low Voltage Power-Amp------IC1&IC2---------UJ37S--------£1.06
3.5mm, 3 circuit stereo phone jack------n/a-------------FK20W-------£1.06
470uf, 16v electrolytic capacitor--------C4-------------VH46A--------£0.23
10uf, 16v electrolytic capacitor x 2-----C2 & C3---------AT98G--------£0.22
0.047uf Mylar capacitor----------------C1--------------WW20W------£0.08
220uf, 16v electrolytic capacitor--------C7-------------VH41U--------£0.11
0.022uf Mylar capacitor x 2-------------C6&C9---------WW19V--------£0.14
9v battery PP3 clip with wires-----------n/a-------------HF28F--------£0.29
150 Ohm resistor 0.125w----------------R1-------------M150R--------£0.09
1K resistor 0.125w----------------------R2-------------M1K----------£0.09
220 Ohm resistor 0.125w----------------R4-------------M220R--------£0.09
Carriage (Maplin)----------------------------------------------------£2.50
Maplins Total-------------------------------------------------------£17.28

You won't need a detuning coil as described in Tony's instructions, but you will need to wire the phono-jack socket correctly. I had a problem getting the soldering of the jack right and I'll post some pictures of the circuit board fitted out for the UK using Maplin components if people need the help.

Tony's website http://pw1.netcom.com/~t-rex/BatDetector.html has all the documents and tips you'll need, and personally I'd go for the enhanced detector, the list above is everything you'll need but the board. The PCB can be bought direct from Tony using PayPal, but if there's enough interest I can stock it in the UK on his behalf and reduce costs all round.

We're also looking a keeping some kits of components and boards in stock too, so if you'd like either a board, or a board and a set of components then e-mail me direct.

Lee