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MrBungle · 11th Jun 2019, 7:21 am

Yes if I owned another one I’d probably stick a crowbar in it!

After consulting with someone at the time it appears that the failure in mine was likely caused by either the LM350K giving up or the setting divider. The precise root cause would have been nice to find but I didn’t look too deeply into it. The 9v unregulated line was at 12 volts and was present on the 5V line which is what killed it all. My excessively high mains voltage here probably was the contributing cause. I’d expect a piece of equipment with that much expensive stuff in it to have a crowbar on the power supply though. A £8 regulator can cost a £500 signal generator.

A TL431, SCR and a fuse (consult art of electronics 3e chapter 9) would be an inexpensive safety precaution.

My only consolation was I only paid £10 for the 2019A off someone on gumtree and it went on to help someone who had a pretty beaten up one with a burned out attenuator because some numpty had decided to transmit into it!

11th Jun 2019, 7:21 am	#9
MrBungle Dekatron Join Date: Jun 2016 Location: London, UK. Posts: 3,687	Re: Marconi 2018 problems Yes if I owned another one I’d probably stick a crowbar in it! After consulting with someone at the time it appears that the failure in mine was likely caused by either the LM350K giving up or the setting divider. The precise root cause would have been nice to find but I didn’t look too deeply into it. The 9v unregulated line was at 12 volts and was present on the 5V line which is what killed it all. My excessively high mains voltage here probably was the contributing cause. I’d expect a piece of equipment with that much expensive stuff in it to have a crowbar on the power supply though. A £8 regulator can cost a £500 signal generator. A TL431, SCR and a fuse (consult art of electronics 3e chapter 9) would be an inexpensive safety precaution. My only consolation was I only paid £10 for the 2019A off someone on gumtree and it went on to help someone who had a pretty beaten up one with a burned out attenuator because some numpty had decided to transmit into it!