[peter.jones]

Purchased a Zoom H2N about a month ago to record off my Pettersson d-230 frequency division detector.

It is a big improvement over the H2, and so far looks to be ideal for recording bats with some really useful features:

* The Auto-record function triggers every time the sound threshold is broken, and creates a new file (including date/time stamp) for each trigger. (I get quite a few false triggers but these are all < 1MB in size, the bat recordings are all >1MB, so extracting the bats is proving really easy. However, I have only used this in my garden to date, and have only picked up Pipistrelles so far! so I need to check it works just as well for other species)

* Battery life is very good.. up to 20 hours (plus it saves all files if the battery runs out during recording. This could be very useful for remote recording)

On the downside it appears a bit flimsy. The Battery cover in particular feels a bit vulnerable, and is a devil to remove.


Will post a follow up here, once I am happy I have it set up for optimal results. I'd also like to experiment with the 4 track recording (two tracks for the bat detector, 2 tracks for the internal mics listening for bird calls)

Peter

[AndyMc]

We're looking forward to hearing your recordings. Hope you get sorted soon.

The wife tried recording with her mobile phone close to the Magenta 5. As expected (by me) the background noise is overwhelming for my ears (she chuffed though).
I'm just wondering if it's a waste of time making her a lead up to fit the line-in socket i.e. will the white noise still be at a high level?

[peter.jones]

Hello Andy,
some recordings form my previous recording device at the link below:

http://bat-diaries.blogspot.co.uk/

They are form the Frequency Division channel of my detector, so won't have the richness of your Heterodyne recorder. But the tempo of the calls will be similar to your detector.

[balkantrek]

Hi Peter,

Very impressed with the sonograms and power spectrums on your bat diary. They are very clear and visually easy to analyse. What analysis software are you using to produce them?

[peter.jones]

Hello,
I use Audacity to extract the section of the file I want and also to produce the power spectrum. Then wavesurfer to produce the sonogram.
Wavesurfer needs to be set up as per the pdf file:
www.bats.org.uk/.../BRM_Wavesurfer_for_sonogram_analysis.pdf

You need to experiment for a bit to get used to Wavesurfer. By tuning the contrast and brightness, and analysis window in the spectogram controls window, you can usually get fairly sharp results

Wavesurfer and Audacity are both free.

[balkantrek]

Thanks for the link to the Wavesurfer set up pdf...its useful to have something that takes one through it step by step.

[AndyMc]

Originally Posted by peter.jones

................so won't have the richness of your Heterodyne recorder............

Or the white noise . Very impressed with the diary.
Thanks also Peter, for the info on FREE software. We may get there one day but one step at a time. We need to learn how to use the 'Het' properly first - reading about it is not the same as getting out with someone with the knowledge.
Hopefully a local group will put something on as the year progresses instead of the general 'not for newbies'. How do they expect the next generation to carry on the good work? They do seem a bit of a tight group so far.

[peter.jones]

Hello Andy,
I'm finding perhaps similar attitude with my local bat group. They don't seem too interested in new members, and you don't se too many young faces in their ranks! My previous local group in North Bucks was brilliant. They had me getting rabies jabs and handling bats within a few weeks!
Still, give them chance. They may be more accommodating once the weather heats up, and there are more surveys taking place.

Peter

[Firepro]

I am a newcomer to Bat Watching and am looking to buy a recorder to use with my BatBox 'Duet'. I would also like to be able to use the recorder for recording bird and other nature sounds. I have done a fair bit of research and at the moment am torn between the Zoom H2n and the Olympus LS-11. I would therefore appreciate any feedback as to how your H2n is performing in the field since your last post.

Best Regards

Peter R

[peter.jones]

Hello,
yes, it's working fine.

A recent Serotine over the house,

Plus some birdsong,


Works well on the remote setting. I just leave the detector running overnight. In the morning the Bats are easily distinguished from the false alarms (of which there can be many!), by their larger file size.

I don't have any experience of other models, but the H2N's strengths are the remote trigger, long battery life, and record level dial.

[Firepro]

Thanks for the update Peter. Glad to hear it's working and for the confirmation of its strong points. I had a look at /listen to the results on your blog - very impressed. Particularly pleasing to see how well it copes with the bird recordings as well as the bats. More food for thought.

Peter R

[AndyMc]

Hi Peter,
Are you involved with the NBMP this year?
Not sure if you already know:
The BCT are particularly interested in folk like yourself, who have your type of equipment. They are looking for enhancements to the project.

[peter.jones]

Hello Andy,
Yes, I do a couple of surveys a year. Not always easy, compared to a casual bat walk. I took part in the Nathusius' pipistrelle survey last September and recorded 1 Nathusius' (my only one ever).

Results have just been confirmed:

http://www.bats.org.uk/pages/nath_pi...y_results.html

Looking at the distribution, that could be a good one for you to go for? They like large water bodies, and are thought to migrate through the UK in Autumn. If you familiarise yourselves with the Common and Soprano Pips, then Nathusius' should be fairly easy to distinguish at least as a "probable", as it is pretty much the same but at lower frequency (~38-41KHz)

Peter

[Horoka]

Greetings from Hokkaido, Japan — this is my first posting here.

I recently bought a Pettersson D240 bat detecter together with a Zoom H2n recorder and then found this conservation while I was googling for ideas. Must say I am very impressed by Peter.Jones's results!

i've been testing my own equipment and so far I've been having problems with the H2n recording the heterodyne and time expansion output from the detector.

The H2n auto record function hasn't worked (although I've had the on/off trigger set at -32 db) and manual recording is very faint, though auto gain (meeting) is on.

I am wondering if I should set the whole thing up in a different way? I'd appreciate some ideas! Thanks.

[peter.jones]

Hello Horoka,
As it's a different set up to mine, I don't know specifics, but I'd turn off the auto gain, and wind the recording level dial up to 5 or 6.
Then set the trigger threshold around -15db then tweak it from there. Unfortunately, you need a bat in order to calibrate it.

I think I mentioned earlier that I get a lot of false triggers. Overnight it could run to a few hundred! but these are all less than 1mb, so are easy to sort and delete. Anything over 1mb, on my set up tends to be a bat, or the occasional animal mooching near the detector etc.

Hope you can sort it. I guess Pettersson might be able to offer some advice if you still have problems. I'm unfamiliar with the strength of TE signals compared to the pretty strong FD signals that come out of the D230, or the auto capturing of signals on the D240.

Peter

[Horoka]

Peter,

Thanks for your help. I had a cooperative bat or two last night — I heard them clearly through both in heterodyne and time expansion, with the Pettersson set to time expansion with auto trigger — but the H2n didn't record anything.

My settings (in more detail) were Pettersson with a 1 metre Sony stereo line cable to the H2n, rec. level dial 6, auto record on, trigger threshold -15db start, -15db stop, auto rec stop 2 secs, pre rec on, lo cut off, Comp 1 (general) on, monitor always on, auto gain off, record format WAV96kHz/24bit, software version 1.00, mic set to XY. (I guess that most of that is irrelevant!).

I'm wondering if I should try a different stereo line cable or SDHC card? What do you think? Thanks, Simon.

[peter.jones]

Hello Simon,
I don't know. your settings are pretty much identical to me, when the bat was around, could you see the signal level on the H2N moving, in fact if you rattle keys or snap your fingers in front of the bat detector you should see the signal levels move, and do they move above the threshold. your cable is stereo both ends?, and did you press record on the h2n, so the red light was on? (sorry if this sounds patronising! I'm just thinking of every possible place where it could go wrong.)

Failing all that, I would forget about the auto record for a while and just get straight forward recordings from the detector to the H2n, so you are happy that the system is working end to end. Then add the auto-record bit once you are happy the rest is working.

The one thing nagging me, is that I don't understand TE recorders, so not sure how the channels are set up to output to the tape. I'm not sure if it works like an FD and sends a constant signal out. The TE wouldn't do this as it would get further and further behind?

[Horoka]

Peter,

Thanks again. Apparently the problem was the stereo line cable. I changed over to another one and the H2n started recording. At first it produced one single long recording, mainly of background noise from the detecter, so I changed the auto record level to -12 dB, and then got a series of recordings (mostly false triggers, but also one good HET/TE recording). (I'm changing it down again to -10 dB.)

The D240 produces a heterodyne signal in the left channel and a time expansion signal in the right one. In practice it seems you don't get both at the same time — I'm not sure how this works — and you can hear them one after the other. Simon

[peter.jones]

Well that's good news. Glad you sorted it.

I get a lot of false triggers, but they are all smaller in file size than the bat calls, and easy to filter out. So I live with them as opposed to tweaking the set up in case I start to drop the real calls.

[Horoka]

Originally Posted by peter.jones

. . . I use Audacity to extract the section of the file I want and also to produce the power spectrum. Then wavesurfer to produce the sonogram.
Wavesurfer needs to be set up as per the pdf file:
www.bats.org.uk/.../BRM_Wavesurfer_for_sonogram_analysis.pdf

I am interested in trying this. I'm on a Mac so I guess I should use Audacity + Wavesurfer (or Raven Lite?), but are there any instructions for setting up the software? Unfortunately the pdf at bats.org pdf has disappeared and I haven't been able to find it anywhere else. Any ideas would be much appreciated!

[peter.jones]

http://www.bats.org.uk/publications_...m_analysis.pdf

Try that Simon. Don't know if the original link was corrupt, but this one worked 5 mins ago,

Peter

[Horoka]

Thanks, Peter. Got the file, but the setup is difficult. The BRM 'sonogram analysis' file is for Windows. Not normally a big problem, but in this case the Mac version is odd. (Amazingly, the settings such as the 'Properties' box are only accessible with control-option clicks — I found this out by experimenting!)

My test sound file isn't playing and I'm getting an error message:

can't read "Info(Prefs,PrintCmd)": no such element in array
can't read "Info(Prefs,PrintCmd)": no such element in array
    while executing
"$proc $notebook.$lowpage"
    (procedure "PreferencesDialog" line 33)
    invoked from within
"PreferencesDialog"
    (menu invoke)

Maybe Raven Lite is better supported? I'm going to start looking at that. Simon

[peter.jones]

Thinking about it, the files from my H2N don't play directly into wavesurfer either. Apologies, I had forgotten about this, as I use Audacity to check the wav files out of the H2N, edit the best bits and export to a wav file (which reads fine in Wavesurfer. Don't know why this is the case)

Peter