Garden watering system.

I will be away for a few days and the seedlings can't be let to get dry at this time of the year. Not much time and I as always work on a budget:  Reviewed the timer tap controllers and sprinklers. Picked a controller from Jaycar and tried a rotating lawn sprinkler.

I thought if the timer software is not good but the hardware is Okay I might gut it and replace it's brains with a Arduino type controller then get all sorts of remote control. The hardware seems fine so far though and the software too. Lets leave it at that for now.

The lawn sprinkler just did not work and stuck after half an oscillation. I returned it an got a simple cone spray that is meant to stick in the lawn. I mounted it upside-down over the main garden and used the timer to set it running for 15 minutes at 6 am and 6 pm. It seems just fine for late spring and did a great job while I was away for 5 days.

Control unit and sprinkler.
 

I might tap into the hose that runs along side of the house with some screw in spray nozzles to water some potted plants to the along there. I put these pots in the empty spots of the garden under the timed sprinkler while I was away and that worked out well but I need that space to let things grow so the pots need to go back.

Then

Now

 I now own an 8 Track player

So I just found an 8 Track Player.....

 A Prinzsound CRD8, Serial # 001429 (thanks man)

I spent a bit of time on it to get it going nicely and it does now. Information on it is very sparse to the point were the above post was the only reference I could find on it.

I want to do a fairly complete post on the fix so that web can preserve the info in case others need it:

I opened the case and the hardware was all quite good. Heads nice and not even very dirty. Only one drive belt in the whole unit and that still has good tension. The power plug was loose so I tidied that up and plugged it in. 

No smoke or bad smells. Plugged in a David Cassidy 8-Track (the tape I cared least for was picked for testing) and it thumped into life ( really does thump. Big fat solenoids ) and plugged my 70 Technics EAH-220 headphones in.

Right channel fine, left channel nothing.

Got to be the rec/play switch. Stripped and cleaned with iso. No difference. Made a quick and dirty audio probe with a guitar amp I had to hand and found the signal disappeared in the left pre-amp just before the volume. 

No service manual to be found anywhere on the web. 

Drew a circuit and overlay then put it back together and started checking voltages on the left channel against the right. Second transistor in the left channel sus; replaced the 2SC871 with a BC549 . Sound in both channels but the left starts quietly then fades to full volume after 10 or so seconds. Replaced various electro' caps to no affect until I looked at the what I had considered the least likely electro which was the cap to the playback head. 

Replacing that fixed it and it now runs just fine. It was quite obviously swollen on removal and had interfered with the bias of the first transistor until the cap in the emitter path had charged up. Finally I put RCA plugs on in place of the DIN plug.

I'll post the overlay and circuit diagram I worked out in as follow ups to this post.

The only real lasting damage is that I now quite like David Cassidy. 

 

PC board overlay: Solder side.

 

 

Circuit diagram of the left channel :

 

2015-09 Line out for the Yamaha CN-70

I got this for $30 or less. I have the room right now and it seemed in good nick and is. I removed an odd mixer that had been added but came without its power supply so was useless. I had been hoping to use it for a line out. (The organ is very well built for service).
That got me thinking about adding a line out. Found a circuit diagram. Found some room on the side panel. Had the parts.

Test Point 82 clearly indicated on the main board is just before the Expression peddle and the main Vol so that's about right. Drilled a hole and made a plate to hold a 6.5mm jack socket.

Mounted it, soldered it up and tried it out.

Noisy but good. I think the way to fix the noise would be to go back toward the tone banks, make a low noise amp and pick it up from there. There'd be no rhythm or auto play stuff that way though but I was toying with giving them their own outputs anyway. Maybe later.
Sounds AWESOME through last months PTOM (a spring line reverb tank reverb. must write it up). Very Marty Rev 

2012-01 Low Noise Phono System

I've always had a little hum on the record player. So low though that even quiet music obscures it.
However it is there and I recently got a copy of Tibetan Bells. TB is very quiet indeed, with long passages where a single bell note fades completely before the next is struck.

[1] Check the amp.
[2] Check the cables.
[3] Check the record player.

Amp:
Found the Tuner input on the amp, which I had been using had some hum. Checked them all: The Tape input is quietest by far.

Cables:
OK.

Record player:
Both check out fine.



OK, the pre-amp in the amp is noisy so I got a general preamp kit from jcar (http://www.jaycar.co.nz/productView.asp?ID=KC5159) to try. Cheap enough to discard if not good enough.
It sounds great. Housed it in an old power supply case and it goes directly to a spare input on the PC sound card.
I can easily hear the original tape noise kick in as the cutting engineer switches it in when mastering the LP on Tibetan Bells so the total noise in the system here is less then in the original studio (1970's analog) and there's no discernible hum at all. An added advantage here is there is no need to use any mechanical switches any more. I just use alsa mixer to directly control the sound-card input level and switch between inputs on the sound card.

Here's a photo of the finished pre-amp disguised as a pedestal.

2010-09 Stereo patch bus

Tired of plugging in various new devices for recording or playback. It's a chore and messy to the point where I'm deferring audio projects on account of it.
Some simple patch panels to allow selecting / routing inputs and out puts are needed.

2010-08 Theremin

A Theremin from a kit but then re-cased to look less ugly and more in keeping with it's ethereal quality.
The case is a wooden box of mystery I found in a junk shop. The kit is the revised one from Jay Car. I did Not add the mods' for more linear tone control or timbre controls. Save that for version II I think.

It's just about what I thought it would be like to play. The volume panel is counter-intuitive in that it's quieter the closer you place you han. I'd like it to be silent until your hand is near.

You adjust the length of the antenna until the tone drops to nothing when your hand is away from it then you're set.

2009-03 Record Player Arm Lifter

A small automaton with an optical sensor to lift the arm of a record player. I'd like to use junk sources for this and targeted a 3" floppy drive to provide the parts.

2008-11 Concrete Record Player

So its to be a record-player then: The Op-shop had some mint diamond styli for a few bucks so I bought them.
My Trusty Luxman skates a little and is too wide for the lundia. I felt like an audio project after all the PC based stuff so the Concrete Record Player Plinth is the POTM.
At last a home for my SME arm. Here you see all the parts I've been putting aside: The bearing, light weight patter and motor from a turntable with a crap arm but completely noiseless and stable - can't recall the brand. All sorts of cartridges and styli collected over the years and of course the pice of tone army resistance: a SME tone arm. Cost me $100(ish) in the 80's from a greedy eccentric who only prized it's resale value.

2008-08 Low power LED light

A low power LED light to replace the filiment lamp that keeps fritzing in my earth globe.

2008-03 Mic pre-amps

I've been using an old cassette recorder for a mic preamp and it fulls up a slot in my shelfs, isn't portable and has a bit too much noise.