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Success Stories If you have successfully repaired or restored a piece of equipment, why not write up what you did and post details here. Particularly if it was interesting, unusual or challenging. PLEASE DO NOT POST REQUESTS FOR HELP HERE! |
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11th Sep 2022, 1:59 pm | #1 |
Diode
Join Date: Sep 2022
Location: Bristol, UK.
Posts: 3
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Hameg HM 307 Oscilloscope Restoration
This story starts back in 1983 when i was teenage studying electronics. Keen to look inside any electronic device my dad gave me a cardboard box of parts and what was clearly an oscilloscope. He found it in a skip at a local college that he was delivering to. The idea was to give me an opportunity to experiment with the scope. To be honest without a schematic or a service manual it was going nowhere. So it go put away in the attic along with other bits and pieces. It stayed in my parents attic until they moved back in 2015 when they gave me this cobweb ridden box contain this old scope in bits. By this time I had my own scope and a busy work life so I wasn't exactly keen to do anything with it.
Then Covid came along and along and with it a lots of free time too. So I dug out the old Hameg out and decided that I would attempt to restore it. Starting with a good vacuum and clean I could see that although in bits, all the necessary parts were there. The electrolytic capacitors was as I expected in need of replacement. All were common values so those all got replaced and then I powered it slowly with a variac. Initially there was an issue with frame collapse which may have been the original reason why it was found in bits. The frame collapse turned out to be a faulty deflection transistor. Once the scope was up and running I used my works recently calibrated Fluke scope as a reference with an signal generator to calibrate the HM 307 with. What was really nice is that I discovered that this scope had a built in component tester in it which worked perfectly. Many thanks for reading. Ian |
11th Sep 2022, 2:10 pm | #2 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,869
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Re: Hameg HM 307 Oscilloscope Restoration
Welcome to the forum!
Plenty of other Hamegs in here. Good basic scopes. David
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12th Sep 2022, 1:24 am | #3 |
Diode
Join Date: Sep 2022
Location: Bristol, UK.
Posts: 3
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Re: Hameg HM 307 Oscilloscope Restoration
Thanks for your reply and warm welcome David.
Have a nice week. |
12th Sep 2022, 12:54 pm | #4 |
Heptode
Join Date: Sep 2010
Location: Hythe, Hampshire, UK.
Posts: 630
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Re: Hameg HM 307 Oscilloscope Restoration
Welcome Ian, what a great lockdown project. The fact all the parts have been in a loft and you have still managed to salvage a working scope out of them is pretty amazing.
Great to see it working and that it had the added bonus of a component tester, well done. |
13th Sep 2022, 12:37 pm | #5 |
Diode
Join Date: Sep 2022
Location: Bristol, UK.
Posts: 3
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Re: Hameg HM 307 Oscilloscope Restoration
Hi Peter,
Many thanks for acknowledging my post. Yes well pleased with the outcome of this project. The easy availability of service manuals online has really helped in restoring this old scope. Regards Ian Bassett M5AXA |
15th Sep 2022, 8:03 pm | #6 |
Octode
Join Date: Nov 2003
Location: Bath, Somerset, UK.
Posts: 1,805
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Re: Hameg HM 307 Oscilloscope Restoration
Nice job Ian. I have the later Indian made version of this Hameg, it is branded Harris. The component test feature is so good that I leave it on that setting and use a Telequipment D32 for general work. It is small enough to keep on the bench so it is always ready.
Neil
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