Ian, Thanks again for this info.......Yes I think you are correct on all 
this, and the results would simply act (a bit) like a Tilt meter.
I am now testing a simple 2 second Tilt meter,(for lack of a better name).
I am please with the recordings, I am posting them at PSN, under the name 
TCIDTM.   Very happy with it so far.
Any advise on this subject is appreciated.

Ted


----- Original Message ----- 
From: "ian" 
To: 
Sent: Monday, February 25, 2008 6:33 AM
Subject: Re: Fw: Long Period Pendulum


> Hi,
>
> I didn't get very far, due to lack of time.  I used a threaded rod which 
> screws through a threaded hole in the body of the pivot.  The rod was only 
> 5mm in diameter and wasn't very strong, so when the pendulum was heading 
> towards each extreme it would bend and the pendulum's motion was very 
> complicated.  My next step would be to try it with a larger diameter rod, 
> one day...
>
> With the limitations mentioned above, I only got 5 seconds out of it and 
> it wasn't stable enough to behave in the way it should, like resting at 2 
> o'clock.  I think the main benefit of an asymmetrical arrangement will be 
> that you get more movement at the bottom end (for a given length) which 
> may make seismic excitations of the pendulum (as a tiltmeter) measurable!
>
> Good luck!
>
> Ian
>
> tchannel1@............ wrote:
>> Hi Ian,  That was my next test,   I want to try this just as you 
>> indicated. What did you find?  Did it change the maximum period possible?
>> Did you find that your experiments, where the pendulum wanted to favor 
>> the 2:  o'clock vs vertical, as you approached longer periods?
>> Thanks, Ted
>>
>> ----- Original Message ----- From: "ian" 
>> To: 
>> Sent: Monday, February 25, 2008 12:49 AM
>> Subject: Re: Fw: Long Period Pendulum
>>
>>
>>> I was playing with something like this but with the pivot near the top 
>>> end of the rod.  The top weight was much bigger than the lower weight in 
>>> proportion to the lengths of the sections above and below the pivot. 
>>> That way, you'll get more movement at the bottom end of the long section 
>>> than you are currently getting with your symmetrical arrangement. 
>>> Balancing is a little more tricky because of the asymmetry.
>>>
>>> Given that this is probably working as a tilt meter, getting a long 
>>> period may not be too important.
>>>
>>> Ian
>>>
>>>
>>> Brett Nordgren wrote:
>>>> Geoff,
>>>>
>>>> I believe that the only problem is that the amplitude of tilt 
>>>> oscillations from quakes would be rather small, and they are only 
>>>> associated with some of the phases.  But it should definitely be worth 
>>>> a try.
>>>>
>>>> Regards,
>>>> Brett
>>>>
>>>> At 01:21 PM 2/24/2008 -0700, you wrote:
>>>>> WHAT WOULD be wrong with building a
>>>>> device that is fixed in a level
>>>>> fashion and measure only tilt since
>>>>> distortions stress and strain in the earth
>>>>> will manifest itself as a tilt ?
>>>>>
>>>>> It may be easier and cheaper to do this ?
>>>>>
>>>>> regards;
>>>>> geoff
>>>>
>>>>
>>>> __________________________________________________________
>>>>
>>>> Public Seismic Network Mailing List (PSN-L)
>>>>
>>>> To leave this list email PSN-L-REQUEST@.............. with the body of 
>>>> the message (first line only): unsubscribe
>>>> See http://www.seismicnet.com/maillist.html for more information.
>>>>
>>>>
>>> __________________________________________________________
>>>
>>> Public Seismic Network Mailing List (PSN-L)
>>>
>>> To leave this list email PSN-L-REQUEST@.............. with the body of 
>>> the message (first line only): unsubscribe
>>> See http://www.seismicnet.com/maillist.html for more information.
>>>
>>
>> __________________________________________________________
>>
>> Public Seismic Network Mailing List (PSN-L)
>>
>> To leave this list email PSN-L-REQUEST@.............. with the body of 
>> the message (first line only): unsubscribe
>> See http://www.seismicnet.com/maillist.html for more information.
>>
>>
> __________________________________________________________
>
> Public Seismic Network Mailing List (PSN-L)
>
> To leave this list email PSN-L-REQUEST@.............. with the body of the 
> message (first line only): unsubscribe
> See http://www.seismicnet.com/maillist.html for more information.
> 

__________________________________________________________

Public Seismic Network Mailing List (PSN-L)