The Geeky Nerdy Project Page

[gldenwetgoose 20,935]

I don't think I've mentioned it here - so now's a good point.

Some 7+ years ago my son was learning guitar.  I'm not musical at all, but a large part of my friends and acquaintances circle were all playing in bands.  I decided on a little side project of my own to 'aid' his enthusiasm.

That geeky project was a valve guitar practice amp...  Only about 2 Watts of power or so, it doesn't need much.  Design has kept in line with classic amps of the '50s & '60s so components on a tag board rather than a modern PCB.

Last night we had some friends visit, and in an attempt to stop the young son being bored, we dug out son's cheap electric guitar and this amp.  It hasn't been used for a few years and one of the curious features of a valve amp - over an hour or so of use, was just sounding better and better.   Like it was waking from it's slumbers.

 

The basis of the amp is a kit from a German company which wasn't over cheap.  But like a lot of projects, that's not the point.   The only silicon in it is a compromise in the power supply board with four discrete diodes forming the bridge rectifier, all the actual amplification being valves.  Four controls are Drive (the preamplifier which can be low for clean tones, or turned up for overdriven distortion), Bass, Treble and Volume.

The rest of the product is too distictive to show here (sorry).   It's built onto an uncycled bedside table.  The lower portion houses an 8" Celestion guitar speaker (10" would have been preferred but wouldn't quite fit).  There's then a shelf with this chassis mounted on it.  And the top has a carry handle.   The rear has a black mesh grille and the whole item is covered in (son's choice) vibrant blue snakeskin leatherette fabric.  My cherry on the top though was getting a sheet of perspex engraved with the knob functions and edge lit with blue LEDs - so the light shows up their names.

Wish I could show it - but it is very unique and identifiable.   Instead, have some pictures of the work in progress.

     

[Sophie 24,220]

4 minutes ago, gldenwetgoose said:

I don't think I've mentioned it here - so now's a good point.

Some 7+ years ago my son was learning guitar.  I'm not musical at all, but a large part of my friends and acquaintances circle were all playing in bands.  I decided on a little side project of my own to 'aid' his enthusiasm.

That geeky project was a valve guitar practice amp...  Only about 2 Watts of power or so, it doesn't need much.  Design has kept in line with classic amps of the '50s & '60s so components on a tag board rather than a modern PCB.

Last night we had some friends visit, and in an attempt to stop the young son being bored, we dug out son's cheap electric guitar and this amp.  It hasn't been used for a few years and one of the curious features of a valve amp - over an hour or so of use, was just sounding better and better.   Like it was waking from it's slumbers.

 

The basis of the amp is a kit from a German company which wasn't over cheap.  But like a lot of projects, that's not the point.   The only silicon in it is a compromise in the power supply board with four discrete diodes forming the bridge rectifier, all the actual amplification being valves.  Four controls are Drive (the preamplifier which can be low for clean tones, or turned up for overdriven distortion), Bass, Treble and Volume.

The rest of the product is too distictive to show here (sorry).   It's built onto an uncycled bedside table.  The lower portion houses an 8" Celestion guitar speaker (10" would have been preferred but wouldn't quite fit).  There's then a shelf with this chassis mounted on it.  And the top has a carry handle.   The rear has a black mesh grille and the whole item is covered in (son's choice) vibrant blue snakeskin leatherette fabric.  My cherry on the top though was getting a sheet of perspex engraved with the knob functions and edge lit with blue LEDs - so the light shows up their names.

Wish I could show it - but it is very unique and identifiable.   Instead, have some pictures of the work in progress.

     

Awesome craftmanship! and I love that it is still getting some use. You should be really proud of it.

[Kupar 13,163]

It's not a geeky, nerdy project, but it's a bit geeky / nerdy I guess. I am feeding the cold birds this winter, and filling the bird bath for them. And the Mpemba effect always pops into my head in this sort of weather. It's the counter-intuitive thing about warm water freezing faster than cold water in some conditions. Really weird: https://en.wikipedia.org/wiki/Mpemba_effect 

Edited January 19 by Kupar

[likesToLick 10,164]

Not my project,  but I wish it was.  I've always wanted a pinball machine, but now I have modified that want, specifically to a 1970s mechanical pinball machine.  

I absolutely loved these two videos, that explain the relay logic of mechanical pinball in detail. 

I actually dabbled with relay logic myself once. In 1975, when I was in high school,  I designed and built a "who's first" answer buzzer system. It was intended to be used for training the school's TV quiz show team.   Unfortunately, it didn't work very well,  as my design didn't compensate for momentum in the relay solenoids,  so it would light up for two contestants if their button presses were very close together.

It was particularly fascinating to see how,  in the first of these youtube videos, the pinball engineers designed the circuit to compensate for some of the physical limitations of mechanical switches.

I want one!

 

 

A huge amount of engineering know-how went into making these machines robust and reliable enough that they could be left unattended in the local chip shop or milk bar,  and still work all day every day.  I am impressed!

[Kupar 13,163]

3 hours ago, likesToLick said:

Not my project,  but I wish it was.  I've always wanted a pinball machine, but now I have modified that want, specifically to a 1970s mechanical pinball machine.  

I absolutely loved these two videos, that explain the relay logic of mechanical pinball in detail. 

I actually dabbled with relay logic myself once. In 1975, when I was in high school,  I designed and built a "who's first" answer buzzer system. It was intended to be used for training the school's TV quiz show team.   Unfortunately, it didn't work very well,  as my design didn't compensate for momentum in the relay solenoids,  so it would light up for two contestants if their button presses were very close together.

It was particularly fascinating to see how,  in the first of these youtube videos, the pinball engineers designed the circuit to compensate for some of the physical limitations of mechanical switches.

I want one!

 

 

A huge amount of engineering know-how went into making these machines robust and reliable enough that they could be left unattended in the local chip shop or milk bar,  and still work all day every day.  I am impressed!

I have watched the first video and I agree - it is just wonderful. I love electromechanical systems on this scale - things you can see (I love the idea of MEMS too, but they are aren't so easily demonstrated, are invariably just a component within a bigger digital electronic system, and don't make such pleasing clunking sounds 🙂).  The presenter is clear and engaging so we'll forgive that the script is somewhat cheesy in places 🙂 

A lovely find - thank you for sharing.

[Paulypeeps 5,133]

One day I will have an Elvira pinball machine. I want to go and stay at Potter's resort just so I can play on theirs.

[likesToLick 10,164]

32 minutes ago, Paulypeeps said:

One day I will have an Elvira pinball machine. I want to go and stay at Potter's resort just so I can play on theirs.

Is this the one you mean?   It looks amazing..

     

 

Link to details in the international pinball database

 

[Paulypeeps 5,133]

It is the older "Scared Stiff" one I am familiar with. That one looks excellent too though.

[Kupar 13,163]

I'm considering building an intercom to connect upstairs with downstairs in the house K and I are moving to shortly (fingers crossed). We will have neighbours whose house joins on to ours, and over the last 20+ years while living in a detached house we've become used to shouting loudly to each other when in different rooms - something we probably ought to not do in future.

I could install a front-door type unit 'off the shelf' but where's the fun in that? I found a neat circuit for a hands-free, always-on wired intercom that looks about right for my limited level of ability.

https://www.redcircuits.com/Page78.htm

But I don't want it always-on. And I don't want it battery powered either. Rather, I want the whole thing to be powered by a 9Vdc supply at one end, with the ability for either unit to switch the power on when communication is needed, and off when it's not. And a means of seeing when it's on or off.

So, friends with electrical / electronics expertise, will this refinement work? I know it looks like I'll end up running a screened wire for the audio and a separate 4-core cable for the power / switching, but I don't think that matters.

 

[Kupar 13,163]

3 minutes ago, Kupar said:

I'm considering building an intercom to connect upstairs with downstairs in the house K and I are moving to shortly (fingers crossed). We will have neighbours whose house joins on to ours, and over the last 20+ years while living in a detached house we've become used to shouting loudly to each other when in different rooms - something we probably ought to not do in future.

I could install a front-door type unit 'off the shelf' but where's the fun in that? I found a neat circuit for a hands-free, always-on wired intercom that looks about right for my limited level of ability.

https://www.redcircuits.com/Page78.htm

But I don't want it always-on. And I don't want it battery powered either. Rather, I want the whole thing to be powered by a 9Vdc supply at one end, with the ability for either unit to switch the power on when communication is needed, and off when it's not. And a means of seeing when it's on or off.

So, friends with electrical / electronics expertise, will this refinement work? I know it looks like I'll end up running a screened wire for the audio and a separate 4-core cable for the power / switching, but I don't think that matters.

 

Oh - and I won't bother with the muting switch in the main circuit.

[gldenwetgoose 20,935]

4 hours ago, Kupar said:

I'm considering building an intercom to connect upstairs with downstairs in the house K and I are moving to shortly (fingers crossed). We will have neighbours whose house joins on to ours, and over the last 20+ years while living in a detached house we've become used to shouting loudly to each other when in different rooms - something we probably ought to not do in future.

I could install a front-door type unit 'off the shelf' but where's the fun in that? I found a neat circuit for a hands-free, always-on wired intercom that looks about right for my limited level of ability.

https://www.redcircuits.com/Page78.htm

But I don't want it always-on. And I don't want it battery powered either. Rather, I want the whole thing to be powered by a 9Vdc supply at one end, with the ability for either unit to switch the power on when communication is needed, and off when it's not. And a means of seeing when it's on or off.

So, friends with electrical / electronics expertise, will this refinement work? I know it looks like I'll end up running a screened wire for the audio and a separate 4-core cable for the power / switching, but I don't think that matters.

 

Just to check my understanding - the plan is that there'll be a switch on the upstairs unit, and a switch on the downstairs - so flicking a switch on either end unit will turn on (if off) or turn off (if on).   The LED on each end will show the status.

On that basis, it looks that power to Unit 1 (on the right) will be provided downstream of that switched arrangement - next to the unit 1 LED and resistor.   But Unit 2 is always going to be powered, since it's directly across the supply.  Instead if you powered Unit 2 from the supply after the switch - by the Unit 2 LED and resistor you'd save on having the unit powered continuously.

Other than that - do you want some sort of chime or call buzzer?  Or just switching on the unit and talking?  I'm guessing the circuit is aimed at the sort of door intercoms you get, where the microphone has fairly low sensitivity, so you talk directly into it and a small speaker.

 

Two other thoughts - depending on your love or loathing for Amazon Alexa, if you had two Echo devices, Echo Dot etc you can speak to Alexa to "Drop in on upstairs" or "Drop in on kitchen" etc to speak between two devices.  Depends how bothered you are about Google listening to every single word that takes place.

And unless you're moving to the flimsiest of cardboard box houses, you may find the walls more insulating than you think...

But then where's the fun in that when you could be on a geeky project!

 

[Kupar 13,163]

1 hour ago, gldenwetgoose said:

 But Unit 2 is always going to be powered, since it's directly across the supply.  Instead if you powered Unit 2 from the supply after the switch - by the Unit 2 LED and resistor you'd save on having the unit powered continuously.

Doh! Yes. Thanks for spotting my error and suggesting the correction 🙂 

1 hour ago, gldenwetgoose said:

depending on your love or loathing for Amazon Alexa,

Yes - I have seen that suggested, but I'm more in the loathe camp 🙂

1 hour ago, gldenwetgoose said:

Other than that - do you want some sort of chime or call buzzer?  Or just switching on the unit and talking?  I'm guessing the circuit is aimed at the sort of door intercoms you get, where the microphone has fairly low sensitivity, so you talk directly into it and a small speaker.

I had assumed we wouldn't need a separate buzzer. I hope to select mics and speakers that will give a reasonable volume at the listening end. The amplifier circuit can deliver 1 watt into an 8 ohm speaker. We'll see if that's enough at breadboard stage. If not, a buzzer refinement may be needed. 

Thank you 🙂

[Sophie 24,220]

I had a little more fun with my SDR!

A lot of weather stations, thermostats and key fobs transmit at 433MHz, and with an antenna and a SDR I can intercept these signals. In other words, why spend £30+ on a weather station when you can snoop on next door's?

I have had mixed results with it, sadly. I'm not sure if it's because of the lack of signals in my area, or the signals themselves, or my setup. One thing I have noticed is I can only use auto gain control, I cannot set the gain manually. If I enter any value I get no signals at all. So I think part of my problem is the AGC is setting the gain to max and all the signals are being blocked by noise.

This was the first signal I picked up and actually my most successful. It must be my neighbours thermostat. 27.3C? Scorchio! I'm unsure what the bitbuffer part is but I picked it up a few times and little else.

I picked this up a little later. It appears to be a weather station of some sort but it seems to be faulty, or I am not picking up the signal properly. Everything is 0.

I particularly like this one. Am I correct in thinking someone in my area has consumed over 4 GW ?! The HT680 Remote Control appears to be a garage door opener? Again I am not sure if the problem is on my end because it shows all four buttons as pressed and the address is 0XFFFFF. I detected another weather station but I only successfully identified the channel, I can assure you it is not 0C with 0% humidity! And finally another power meter, but again all 0.

Last but not least, another power meter but I do not believe I captured the signal successfully. Not consuming gigawatts of energy this time! I do not know what "energy count 3000" means.

 

[Kupar 13,163]

5 hours ago, Sophie said:

I particularly like this one. Am I correct in thinking someone in my area has consumed over 4 GW ?!

Err ... the output of Drax power station is about 4GW. But I don't think it uses a domestic Danfoss thermostat 🙂  Some mistake somewhere surely?!

Energy Count 3000 is a data logger made by Voltcraft I think. I found this online:

"Voltcraft “Energy Count 3000” [13] uses 868-MHz radio for communicating and is more energy efficient than any other evaluated platform. As disadvantage, it provides no support for an IP gateway and thus can only be accessed via handheld remote panel with low range. Energy Count 3000 lacks usability of a web or mobile interface, which makes this platform more applicable for technical enthusiasts. All in all, we think that the analyzed related works lack energy efficiency and usability. We tried to conquer this by developing a specialized radio protocol and hardware to significantly reduce energy consumption of measuring devices and provide a versatile back-end to generate helpful front-end applications that help improve the energy efficiency of regular households."

Looks like you have been having fun 🙂 and that is always lovely to see

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