Jump to content

Electronics help needed

johnie

By johnie
in The Lounge

 Share

Recommended Posts

johnie

johnie

Posted
Posted

Can anyone with an understanding of electronics help me? I'm trying to fix an old garage door style remote control.


A component has snapped off the circuit board, and I'm not sure what it is. I think it may be the transmitter crystal or something. It has (had) two legs - these have snapped. It is labelled 57.768 UNI 97 - A. I've attached a couple of photos. The component sat next to the green thing in the area labelled X1.


Thanks for any help.

Link to comment
https://www.eastdulwichforum.co.uk/topic/169809-electronics-help-needed/
Share on other sites
bargee99

bargee99

Posted
Posted
Hi Johnie. X refers to a crystal. It determines the frequency that the circuit resonates at so that it only operates the appropriate receiver. Without further investigation I would guess it has a frequency of 57.768MHz which are the numbers on the can. Hope it helps.
ianr

ianr

Posted
Posted
It looks to be an oscillator from the HC-49U series: http://www.dutchforce.com/~eforum/index.php?s=2e1b2f0b4cdbaa50b92f083a4a057de0&showtopic=980. They seem to be available for a pound or two: just search on HC-49U. The problem is finding one of the right frequency (and maybe other parameter values), but there are several distributors you can ask.
johnie

johnie

Posted
  • Author
Posted

Thanks all for your help! From my research so far I've not found anything with the 57.768MHz frequency, but I'll press on.


Graham, I had considered that, but the breaks are so clean there is nothing to solder to, at least not with my rubbish skills and failing eyesight.

ianr

ianr

Posted
Posted

You could always try a bit of surgery on the can to gain access; even buy a few of the type to experiment with first.


Speaking of which, I'm thinking of trying to replace a few suspect capacitors on my PC's motherboard, after it ceased functioning without any obvious cause. But I'd prefer get some practice first. Does anyone have a derelict motherboard they don't want that I could use?

bargee99

bargee99

Posted
Posted

Hi Johnie,

CPC sell the same kind of crystal for 70P each but only have them up to 50MHz. If there is a similar crystal in the receiver you may be able to pair them up by changing the one in the receiver as well to make them work together,

http://cpc.farnell.com/ael-crystals/x50m000000l001/crystal-50mhz-hc49u/dp/SC08184

Abe_froeman

Abe_froeman

Posted
Posted

I would have thought yo would be able to buy an entire replacement zapper for less than a tenner on ebay or similar. Is there any text on the casing that would indicate what make / frequency it is?


I did this once with a replacement for an electric gate remote and all I had to do was put a battery in and set the switches numbered 1 to 10 to the same position as the old remote

johnie

johnie

Posted
  • Author
Posted

Hi Bargee


The remotes are for security shutters on an office block. There are two working remotes and this broken one, so I can't modify the receiver. But a good suggestion.


Hi Abe


Yes, you would have thought so, but no such joy. The shutters are about 30 years old I think. The fact I can't find a crystal with the 57.768 anywhere makes me think it may be a red herring, as I have found a couple of 7.68 Mhz ones (at 44p with ?12.50 postage!).


Does anyone know if there is some way to measure the frequency from one of the working remotes?

DulwichFox

DulwichFox

Posted
Posted

johnie Wrote:

-------------------------------------------------------

> Hi Bargee

>

> The remotes are for security shutters on an office

> block. There are two working remotes and this

> broken one, so I can't modify the receiver. But a

> good suggestion.

>

> Hi Abe

>

> Yes, you would have thought so, but no such joy.

> The shutters are about 30 years old I think. The

> fact I can't find a crystal with the 57.768

> anywhere makes me think it may be a red herring,

> as I have found a couple of 7.68 Mhz ones (at 44p

> with ?12.50 postage!).

>

> Does anyone know if there is some way to measure

> the frequency from one of the working remotes?


Hi Jonnie. I have a device that does just that.


http://mklec.com/image/cache/data/etc/gooit_frequency_counter-7-500x500.jpg


You are welcome to borrow it. You will need to supply a PP3 9v battery


DulwichFox

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing
  • Advertise Here

  • Latest Discussions

    • Blah Blah
      Councillor McAsh defects to the Greens

      By Blah Blah · Posted

      Morally they should, but we don't actually vote for parties in our electoral system. We vote for a parliamentary (or council) representative. That candidates group together under party unbrellas is irrelevant. We have a 'representative' democracy, not a party political one (if that makes sense). That's where I am on things at the moment. Reform are knocking on the door of the BNP, and using wedge issues to bait emotional rage. The Greens are knocking on the door of the hard left, sweeping up the Corbynista idealists. But it's worth saying that both are only ascending because of the failures of the two main parties and the successive governments they have led. Large parts of the country have been left in economic decline for decades, while city fat cats became uber wealthy. Young people have been screwed over by student loans. Housing is 40 years of commoditisation, removing affordabilty beyond the reach of too many. Decently paid, secure jobs, seem to be a thing of the past. Which of the main parties can people turn to, to fix any of these things, when the main parties are the reason for the mess that has been allowed to evolve? Reform certainly aren't the answer to those things. The Greens may aspire to do something meaningful about some of them, but where will they find the money to pay for it? None of it's easy.
    • Jules-and-Boo
      Councillor McAsh defects to the Greens

      By Jules-and-Boo · Posted

      Yes, but the context is important and the reason.
    • snowy
      Councillor McAsh defects to the Greens

      By snowy · Posted

      That messes up Wales, Scotland and Northern Ireland - democracy being based on citizenship not literacy. There's intentionally no one language that campaign materials have to be in. 
    • Dogkennelhillbilly
      Councillor McAsh defects to the Greens

      By Dogkennelhillbilly · Posted

      TBH if people don't see what is sectarian in the materials linked to above when they read about them, then I don't think me going on about it will help. They speak for themselves.  I don't know how the Greens can justify promising to be a strong voice for one particular religion. Will that pledge hold when it comes to campaigning in East Dulwich (which is majority atheist)? https://censusdata.uk/e02000836-east-dulwich/ts030-religion

East Dulwich Forum

Established in 2006, we are an online community discussion forum for people who live, work in and visit SE22.

Home
Events
Sign In

Sign In



Or sign in with one of these services

Search
×
    Search In
×
×
  • Create New...