Ham Radio Workbench Podcast Episodes

HRWB 170 - Designing the Murphy Bench with Thomas Witherspoon K4SWL

12/13/2022

SHOW NOTES

Function generator:
https://www.koolertron.com/koolertron-80mhz-programmable-signal-generator-3-5in-screen-display-high-precision-dual-channel-arbitray-waveform-frequency-meter-300msa-s.html
RCMP and Sinclabs:
https://www.ctvnews.ca/politics/rcmp-suspends-contract-awarded-to-company-with-ties-to-chinese-government-1.6186669
Magnifying lamp from Harbor Freight:
https://www.harborfreight.com/fluorescent-magnifying-lamp-60643.html
More lighting
https://www.amazon.ca/Cabinet-Lighting-Wardrobe-Workbench-Black-Warm/dp/B07JQCVX49/ref=asc_df_B07JQCVX49/

Magnetic Helping Hands Soldering Third Hand - PCB Circuit Board Holder with 3X LED Magnifying Lamp, 360 Hot Air Gun Holder, Extra Large & Heavy Duty Base Plate | Flexible Arms for Soldering Stationhttps://www.amazon.com/Magnetic-Helping-Soldering-Magnifying-Flexible/dp/B09MTM94V1/ref=sr_1_5?crid=Y7ZIVVDZ9Y26&keywords=noevsbig&qid=1668635642&sprefix=noevsbi%2Caps%2C518&sr=8-5
MyNoise
https://mynoise.net/

3 Comments

Bill Waggener link

12/19/2022 19:31:04

I enjoyed this show, as I do most. My ears perked up when you all were discussing Mark's grounding ring. As an electrical and telecom contractor for 38 years (now retired) one of our gigs was installing and testing grounding rings at fiber optic nodes belonging to a very large 3-letter legacy telecom company.
The "thermite" process George referred to is in fact "exothermic welding." The trade (generic) term is "cadwelding," in 'honor' of a company makes the stuff. If the connections between the rods and wire are to be buried or encased in concrete such as a footing, cadweld is the only way to go for a lifetime, low resistance connection. Even though there are mechanical connectors that are UL listed for direct burial and/or concrete encasement, the approvals satisfy the National Electrical Code for grounding AC systems, but might not be the best for RF grounding.
An interesting aside: Every now and then a ring would fail the customer's rigid ground resistance test due to sandy and/or rocky soil To mitigate that we would use a (safe) compound to treat the soil around the rods making it more conductive.
Thanks for the great shows guys. Helps me get through boring workouts at the gym.
Bill KG6DZ

Charlie G4JQX

12/22/2022 04:46:55

Great show guys, always full of useful inspiration.
I made a "Murphy Bench" earlier in the year - but I put mine on small 1" heavy duty wheels. Its actually one of those old computer desks that were around in the 90's that I repurposed and it works well. The old keyboard "pull out" drawer is where I keep many common components as it saves me hunting in my main storage boxes. The reason for the wheels is quite simple; I cover a lot of ground in the hobby - from 1930 receiver restoration, boat anchor restoration and repair through to modern electronic design and build, plus I am a CW operator as well. Boat anchor restoration needs a very solid bench and can take a lot of time, so I have a dedicated bench for this (with isolation transformers and HV supplies and so on). I then have another bench for the modern projects. I made both work benches the same height but they are remote from one another - and then I made the mobile Murphy bench the same height. The Murphy bench holds all the precision tools, soldering station, magnifying stuff etc. and has its own power distribution. Then, I can wheel the Murphy bench to the equipment Im working on, put it at right angles to the work bench - plug it in - and away I go. Boat Anchor repairs take ages, especially when Im having to fabricate something or wait for some exotic valve to be found at a ham fest - so I can leave everything set up, knowing my precision tools etc can simply be wheeled away to the other projects. It also goes elsewhere round the house - in the summer months I can wheel the Murphy bench to where the daylight is better when Im building with SMT (important here in the UK!). Repairs to the operating station are easy as well - just wheel it up and everything is there.
The puck and monitor idea was inspired - thank you. Im looking at getting a high res monitor mounted on the murphy bench and a small puck PC underneath, so all my data is accessible and the internet always there too. I think I will be able to add a small PC microscope to it as well, so it too, can be displayed on the monitor. I think this will involve a rebuild of the bench - so that is a forthcoming attraction when Winter really kicks in.
Thanks again!
Charlie G4JQX

Robert G Clark

1/15/2023 22:42:27

I ran across this a thought about this episode.
https://www.familyhandyman.com/project/how-to-build-fold-down-workbench/

HRWB 170 - Designing the Murphy Bench with Thomas Witherspoon K4SWL

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