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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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15th Oct 2019, 12:39 pm | #21 | ||
Heptode
Join Date: Jan 2008
Location: Durham, County Durham, UK.
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Re: Don't shoot me... but ideas wanted about Bluetooth adaptation of DAC90A
Quote:
https://www.screwfix.com/p/lap-usb-c...e/151CC?tc=QT7 John |
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15th Oct 2019, 1:19 pm | #22 |
Dekatron
Join Date: Oct 2003
Location: Southport Lancashire, UK.
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Re: Don't shoot me... but ideas wanted about Bluetooth adaptation of DAC90A
To go back to the start, I found that my pantry transmitter was becoming more and more unusable due to RF rubbish from SMPSs. Putting a class x capacitor inside a 13A plug and trying it in different sockets helped immensely and has made it possible to use it again. It didn't help for LW, though.
A bluetooth receiver would use the full potential frequency response of the amplifier so would sound a lot better than using a pantry transmitter, and be an interesting modification, but it might be worth trying to see whether a capacitor in a plug helps with the interference problem with other sets. Just be careful of the small charge held in cap if you unplug it!
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15th Oct 2019, 1:55 pm | #23 |
Dekatron
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Re: Don't shoot me... but ideas wanted about Bluetooth adaptation of DAC90A
What temperature do you get inside a DAC90?
You might want to check the temperature range that the Bluetooth device can stand. I would just stick a zener at the bottom of the heater chain and then smooth the resulting asymetric squarewave that results, making sure it was powerful enough to stand the switch-on surge. |
15th Oct 2019, 2:45 pm | #24 | |
Rest in Peace
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Re: Don't shoot me... but ideas wanted about Bluetooth adaptation of DAC90A
Quote:
Also the zener must be substantial enough to withstand the full heater current. Your circuit would still require a series rectifying diode before the smoothing cap. to overcome the "square wave " problem i.e. to stop the cap. partially discharging back into the circuit during part of the cycle. The point you make about the ambient temperature is very valid, and certainly should be a consideration in a DAC90a. Tony. Last edited by boxdoctor; 15th Oct 2019 at 2:50 pm. |
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15th Oct 2019, 6:01 pm | #25 |
Dekatron
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Location: Seaford, East Sussex, UK.
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Re: Don't shoot me... but ideas wanted about Bluetooth adaptation of DAC90A
This was my suggestion. Might need some protection from failure of bulbs and bypass resistor (put the assembly in a bag to catch the contents?).
Pauls suggestion is much the same except a series resistor/capacitor is used as a capacitor dropper but that would also need protection as a change in load would result in over voltage. Last edited by PJL; 15th Oct 2019 at 6:09 pm. |
15th Oct 2019, 6:13 pm | #26 | |
Dekatron
Join Date: Aug 2003
Location: near Reading (and sometimes Torquay)
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Re: Don't shoot me... but ideas wanted about Bluetooth adaptation of DAC90A
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15th Oct 2019, 6:20 pm | #27 |
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Re: Don't shoot me... but ideas wanted about Bluetooth adaptation of DAC90A
There are lots of possible solutions. I think Nick is experienced enough to know he needs to experiment.
Keep it simple I say |
15th Oct 2019, 6:40 pm | #28 |
Dekatron
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Re: Don't shoot me... but ideas wanted about Bluetooth adaptation of DAC90A
Opps - yes you are right boxdoctor, you do need a diode.
My brain is working too slowly these days - the heater chain acts like a constant current feed so the voltages doesn't really matter. |
16th Oct 2019, 9:57 am | #29 |
Rest in Peace
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Re: Don't shoot me... but ideas wanted about Bluetooth adaptation of DAC90A
No problem GMB. . I am of an age where senior moments occur, and your comment had me wondering for a while whether I had got it wrong ! Tony.
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16th Oct 2019, 10:50 am | #30 |
Heptode
Join Date: Apr 2016
Location: Cheltenham, Gloucestershire, UK.
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Re: Don't shoot me... but ideas wanted about Bluetooth adaptation of DAC90A
I'd try a pantry transmitter anyway first - that way you can have 'live' radio [news/weather forecasts] FM/DAB/Net ... anything, streaming into all your sets .... not just the DAC90A .... and it leaves it 'totally original' too.
Mind you - one problem with the DAC 'occasional consolettes' is the directional nature of the internal aerial ...... not to mention energy consumption and associated heat! The one big advantage of Nicks proposals is that of 'remote control' i.e. he can alter programme material and volume etc. without leaving his chair!
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