Ralph, I wonder if you could give a bit more detail on your 555-based transmit circuit. Chris Long is building another unit and considering whether to go...
Light transmission. Over the last few weeks I have been looking at light transmission. I brought some trial lenses 10 inches by 7 inches for $4.29 from...
Hi Murray, If it's any comfort, the only sources for the BPW34 in Aus are either RS or Farnell. However, you do get a lot of bang for your buck with that ...
... Thanks very much. The first thing is to get some interest here. I suppose you can talk to your self via a mirror. I am going to try SSTV pic's this will be...
Murray, If you're after a wideband and sensitive Rx, try this: http://users.bestweb.net/~hobbs/frontends/can15q.pdf The circuit on page 19 (Bootstrapped...
Hi Guys, I have been interested in optical communications for a very long time and hearing about the record breaking distance achieved thought I would put a...
... I am about to do the same thing. I will be very interested in your progress. I have made the boxes seperate one TX one RX to try it over a path and get ...
G'day John, Sounds like you're well on the way to having a working system. My understanding of the circuit is that, with the standard circuit, the gate leakage...
John, One other thought. As I said, the input impedance to the FET is extremely high, and important in the biasing. Therefore, it would be wise to have...
Do you need heatsink on the 3 watt luxton LED? I notice it's got a aluminium case. Would a Diacast box be enough? Also how big a heatsink is required for the...
Hi Murry, I used the diecast box as the heatsink. It works well and only gets hot after about 3 hours of continuos operation , so far so good. regards Ralph...
G'day Murray, According to the datasheet: http://www.lumileds.com/pdfs/DS46.PDF The Luxeon III is more like 4.5 watts. It shouldn't be run for more than a...
John, Here's the reply from the Mike Groth regarding your problem. Regards, David Smith. ... Dear David, Thanks for the email. I checked up on the question...
I built mine in a diecast box. The lumiled is on the diecast box with white heat compound. The MJ15003 is on a heat sink. The resistors one 10w 3.3 ohm and 3.9...
... Today I mounted a small computer fan to keep the resistors cool. Now the whole thing including the MJ15003 is quite cool. I will run it for a while to see...
Yep the rx is now going. We are on the edge of the city. There are no street lights visible from our place except one light up the hill. The street light hum...
Hi Murray, Good to hear you got the receiver going and being able to receive the hum reflected off the clouds! Did you build the receiver as shown on the web...
... Hi John, I used K3PGP, MPF-102 AND 2N5088 circuit I got the 2N5088 from South Island componate center in Christchurch. I built it on a home made PC Board ...
To ALL Now that I have built a receiver does anybody have a power hum filter say with a 741 or double 741 equilvant say to put between the K3PGP, MPF-102 AND...
http://www.dse.co.nz/cgi- bin/dse.storefront/43c0b6d005ba1e9a273fc0a87f990752/Export/catalogs/SUP 1000101 Have a look at the Dick smith equivlant charts 73...
http://www.sicom.co.nz/xurl/PageID/2214/function/viewprd/prd_id/68315/c ontent.html Also Altronics 2001 catalogue list them as Z1246 but on web nothing. 73...
BC179 TO-18 PS 20 25 100 0.3 10 125-500 2 150 10 300 G.P. S.S. Amp. BC159, BC309, BC214 The site did not work straight from the url The equivlants are...
Hi Murray, I built a bandpass filter that cuts off at 300Hz and 5kHz - the upper one to cut out the PWM carrier frequency. It consists of cascaded 4-pole...
As anyone who has tried one of the red Luxeon III's will know, they are incredibly bright and should not be viewed directly for any length of time. My Tx...
... I built a bandpass filter that cuts off at 300Hz and 5kHz - the upper one to cut out the PWM carrier frequency. It consists of cascaded 4-pole active...
Hi Murray, The circuits for the low-pass and high-pass filters were attached to the previous email. As for the layout, that was done ugly-style on Veroboard...
Chris Long has asked me to pass on to the group that he will be giving an updated version of his Optical Communications presentation to the Eastern and...
Hi David, Any chance of video recording the up-coming optical group meeting? I'm sure the group members who cannot attend would learn a lot from the video. I...
Hi John, Chris has created a DVD of his presentation and that's probably what he'll play to the meeting. Either that or a Powerpoint show (if there's a laptop...
