Tuesday, March 29, 2011

PHYS 101/102 #1: Electromagnetic Waves

Restoring a Franz Hermle Westminster chime movement



I'm restoring an Hermle clock movement that has Westminster chimes. This is the most complicated clock movement i've attempted yet. It has 3 gear trains, 3 barrel springs, 5 hammers, and it's own xylophone!

Was able to get everything back together and the clock ticks and chimes. Still working on the chiming part of it however.

From the photos you can see how complicated this one is to put back together, especially for an amateur clock repair enthusiast.

Sunday, March 27, 2011

Radar imaging a 12 oz soda can through a 4" solid concrete wall


I've posted some of the near-real-time radar imagery from my dissertation on youtube from the phased array portion of the dissertation.

Shown here is a 12 oz soda can moving from left to right through a 4" thick solid concrete wall. Image is in range vs. range. Can is about 30' from front of radar, radar front is at bottom of image. Image rate of about 0.5 Hz.

Had alot of fun with this project and I continue to work on a more sophisticated variant of it.

Friday, March 25, 2011

Introduction to Radar Systems at MIT Lincoln Laboratory online Videos

For those who are interested in learning about radar systems:

MIT Lincoln Laboratory has posted videos of all lectures of the Introduction to Radar Systems Workshop instructed by Dr. Robert M. O'Donnell.

Friday, March 18, 2011

New Haven Clock Company Tambour No. 16 movement


Video of New Haven clock movement in action, it was awesome to see this one start to go.

Saturday, March 12, 2011

restoring a New Haven Clock Co. Tambour No. 16



Movement is now re-assembled. Mainsprings have been lubricated and bushings oiled. Was really hard to wrestle the main springs back into the movement, had to use wire ties to hold them together.

Thursday, March 10, 2011

restoring a New Haven Clock Co. Tambour No. 16



Re-assembling the clock movement and wrestling with mainsprings! Will have many blisters on my hands before this restoration is complete. All bushings feel OK.

Tuesday, March 8, 2011

restoring a New Haven Clock Co. Tambour No. 16



Using the cleaning solution described in TM 9-1575 i cleaned all of the clock parts. The parts look noticeably more clean than before.

Sunday, March 6, 2011

Restoring a New Haven Clock Co. Tambour No. 16



Tried to run the movement, unfortunately oiling was not enough and it would only go for about 1 minute. For this reason I will have to take the movement apart completely and clean it.

Saturday, March 5, 2011

SAR Imaging of Northeastern University Campus


Shown here, SAR imagery from Eric Williams, Spiros Mantzavinos, Kate Williams, and Galia Ghazi using their IAP 2011 radar system. Excellent outline of buildings shown, this imagery is exactly what we expected from the IAP radar system.

Be sure to check out additional RTI and DTI results and discussion on Eric's website here:

Friday, March 4, 2011

restoring a New Haven Clock Co. Tambour No. 16


I've decided to restore an old New Haven Clock Co. Tambour No. 16 mantel clock. My fiancee purchased this clock at a second hand store for $30. It's really rough but it has potential.

Mechanical clocks are interesting because it is not often that a piece of machinery built a century ago is still useful today.

Thursday, March 3, 2011

Transistor radio hack: playing an Ipod through a vintage 1957 Emerson 888 Pioneer Transistor radio

Vintage sound anywhere with old audio chain. Listen to your favorite oldies in the radios that they were meant to be played on.

Just completed restoring then hacking an Emerson Model 888 Transistor Radio. This radio was built in 1957 and uses a total of 8 transistors.

I restored it following the usual antique radio restoration procedures here:
http://glcharvat.com/website%20pdfs/MIT_Haystack_Open_Lunch_Oct_21_09.pdf

I then modified it so that the ear phone audio output jack would work an an audio input jack by locating the envelope detector and re-wiring the ear phone in-line with the envelope detector and the volume potentiometer as shown in the schematic here:  http://glcharvat.com/website%20pdfs/trans_radio_hack.pdf


More photos and info about this project is shown here:
http://www.glcharvat.com/Dr._Gregory_L._Charvat_Projects/Emerson_Trans_Photos.html

Anyone can do this project, it is very simple and fun!

Wednesday, March 2, 2011

NXP High Power RF Design Challenge

NXP, who makes high power RF MOSFETS has issued a design challenge to make something interesting out of their latest line of MOSFETS.


I am a huge fan of RF power MOSFEST and have found that modern versions are remarkably easy to work with.

Although the deadline for this contest is Feb 27, it has been extended somewhat to invite further entries.

Radar Systems and SAR suggested reading

I have been asked by a few students from the January radar course what books they should read to learn more about SAR and radar systems in general.


Here is a list of excellent books in order of how I learned SAR followed by radar system design:


Introduction to Airborne Radar