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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets.

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Old 4th Nov 2019, 7:54 pm   #1
squegging
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Default Bat detectors again

Hi all,

Digging around for info on this subject, I note an old post here:
https://www.vintage-radio.net/forum/...d.php?t=102454 and wondered if anyone has anything to add regarding ultrasonic mics or useful circuits for heterodyne detectors?

I came across a Knowles MEMS mic SPU1410LR5H-QB which is described in their application note 17: https://www.digikey.co.uk/en/pdf/k/k...ms-microphones as having a useful if peaky response to 100kHz.

Just wondered if anyone has used this successfully as it looks a little tricky to solder, and I am unsure how it would interface with the NE612 mixer design referred to in my first link.

In the meantime I await some Panasonic electret mic WM-61
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Old 4th Nov 2019, 8:14 pm   #2
Electronpusher0
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Default Re: Bat detectors again

I built a Magenta MkII bat detector some years ago and it is very effective, indeed I still use it. This a hetrodyne type using an electret capsule.
https://www.magenta2000.co.uk/acatal...ctor_Mk_2.html
I have detected Pipistrelle, Daubenton's and Lesser horseshoe.

Peter
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Old 5th Nov 2019, 9:13 am   #3
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Default Re: Bat detectors again

I have just read the thread linked in post #1 and have discovered that the Lesser Horseshoe transmits at 110kHz which makes my Magenta II more impressive than I thought.
We saw the Lesser Horseshoes coming out of a house roof in a village beside the Mon and Brec canal in Wales. I had the detector with me and was suprised to find I could not detect anything on its usual setting and had to retune. It was dark so I did not see what the frequency was at the time. The reason I know they were Lesser Horseshoe is that there was a notice posted telling us what they were.

Peter
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Old 5th Nov 2019, 11:02 am   #4
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Default Re: Bat detectors again

I also built the Magenta mk2 kit and it worked very well. It was most sensitive around the 30Khz -50Khz range but dropped off considerably either side of this. I think it is down to the type of condenser microphone they used.
Spent many late summer evenings watching and listening to the bats around the 40Khz mark.
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Old 5th Nov 2019, 12:33 pm   #5
Martin G7MRV
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Default Re: Bat detectors again

Quote:
Originally Posted by squegging View Post
Hi all,

Digging around for info on this subject, I note an old post here:
https://www.vintage-radio.net/forum/...d.php?t=102454 and wondered if anyone has anything to add regarding ultrasonic mics or useful circuits for heterodyne detectors?

I came across a Knowles MEMS mic SPU1410LR5H-QB which is described in their application note 17: https://www.digikey.co.uk/en/pdf/k/k...ms-microphones as having a useful if peaky response to 100kHz.

Just wondered if anyone has used this successfully as it looks a little tricky to solder, and I am unsure how it would interface with the NE612 mixer design referred to in my first link.

In the meantime I await some Panasonic electret mic WM-61
That was my original post, from about 5 years ago - and re-reading it, ive realised that I never used those WM61's! Im not even sure where they are!

SO theres a winter project - find those mics from among my stash, and upgrade my bat detector!
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Old 5th Nov 2019, 1:59 pm   #6
squegging
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Default Re: Bat detectors again

Quote:
Originally Posted by Martin G7MRV View Post
Quote:
Originally Posted by squegging View Post
Hi all,

Digging around for info on this subject, I note an old post here:
https://www.vintage-radio.net/forum/...d.php?t=102454 and wondered if anyone has anything to add regarding ultrasonic mics or useful circuits for heterodyne detectors?

I came across a Knowles MEMS mic SPU1410LR5H-QB which is described in their application note 17: https://www.digikey.co.uk/en/pdf/k/k...ms-microphones as having a useful if peaky response to 100kHz.

Just wondered if anyone has used this successfully as it looks a little tricky to solder, and I am unsure how it would interface with the NE612 mixer design referred to in my first link.

In the meantime I await some Panasonic electret mic WM-61
That was my original post, from about 5 years ago - and re-reading it, ive realised that I never used those WM61's! Im not even sure where they are!

SO theres a winter project - find those mics from among my stash, and upgrade my bat detector!
Well, let us hear how you get with those WM61's
The Knowles MEMS mics sound interesting....

Keith
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