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H.J.Gelsthorpe

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About H.J.Gelsthorpe

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    RC-Cam Visitor
  1. H.J.Gelsthorpe

    TELEMETRY ANTENNA

    Thanks again Mr R.C.Cam,for your indepth reply I am using the T7G transmit module and the R7G recvr.module which is in very good agreement with your asessment alink to the pdf can be found here http://www.okwelectronics.com/datasheets/radio_modules/DS307-7.pdf
  2. H.J.Gelsthorpe

    TELEMETRY ANTENNA

    Thank you for your reply Mr R.C.Cam, I meant a 1/4 wave with and without a ground plane. As you correctly state a dipole would be to large in most models. I will look into your helical anttenna suggestion,I may not stick with 433 mhz band this is a prototype and i am keeping the rf transmitter as a seperate module/ pcb to allow chopping and changing.
  3. H.J.Gelsthorpe

    TELEMETRY ANTENNA

    Thank you Ron for the reply,i was considering the antenna for the plane where it is difficult to get a neat installation with a ground plane. Is the 1/2 wavelength multiples to ensure that voltage and current is arriving at the attenna in phase?.Would that make the worse case odd multiples of 1/4 wavelength? so all other things being equal what extra loss might be expected from a non ground plane transmitter antenna vers. a ground plane xmt attenna
  4. Hello all I am building a altimeter+ vario with data sent over a 434 mHz link. data rate is 1200 bps but transmitted at 2400 bps because of Manchester encoding. Can I just expose the necessary 1/4 wavelength of coax on the transmitter without a ground plane without significantly reducing range? would I be better off with a half wave dipole? and if so how would I match it to the 50 coax?
  5. H.J.Gelsthorpe

    Surface Mount Pcb's

    Thanks For taking the trouble for your replies,some of the results in the pics are very profesional. Has anybody built one of those homemade reflow ovens? or tried the hot plate method? sorry about me shouting earlier Henry
  6. H.J.Gelsthorpe

    Surface Mount Pcb's

    HELLO ALL, HAVE BUILT SOME CONVENTIONAL CCTS USING THROUGH HOLE COMPONENTS AND MY HOMEMADE UV BOX. I NOW WISH TO MOVE ON TO SMT METHODS, SO I HAVE SEVERAL QUESTIONS TO RAISE. WHAT METHODS DO YOU EMPLOY TO SOLDER THE COMPONENTS, IRON AND FINE GUAGE SOLDER OR PASTE AND SOME FORM OF REHEAT? IF YOU GO WITH THE PASTE AND REHEAT METHOD IS A SOLDER MASK ESENTIAL ? WOULD THE ANSWERS BE DIFFERENT IF LEADFREE SOLDER/PASTE WAS USED? IF ANBODY HAS BUILT SOME CCTS USING EITHER OF THE ABOVE METHODS COULD THEY PLEASE POST SOME PIC'S SO THAT I CAN SEE WHAT IS ACHEIVABLE THANKS HENRY
  7. H.J.Gelsthorpe

    HD PICTURE

    Thanks Kilrah When you read the blurb on these devices they give the impression they can work wonders with an SD source,still i suppose they want to shift them. However on a personal note i have a 36" crt tv (toshiba 36zp46) and the picture is very good it performs some form of internal doubling i believe its called picture frame 2, granted that the signal source is digital (freeview). Other television manufacturers have their own systems e.g. phillips pixel plus Now the manufacturers have spotted a gap /niche in the market during the slow transition from sd to hd in uk and rest of europe?. So as an interim measure come out with these picture enhancements, so is this totally different from upscaling? Regards Henry
  8. HELLO ALL The subject of hd transmission has been raised before,however due to limitations of our analogue video links it was ruled out. Has anybody considered using a video upscaler such as Lumagen or DVDO on the ground station to feed a hd set or quality pc monitor. regards Henry
  9. heckO ALL, JUST WONDERING IF A 16:9 FORMAT VIDEO CAMERA WOULD BE ABLE TO SEND A TRANSMISSION VIA THE CURENT BREED OF VIDEO XMTRS/RCVRS TO A WIDESCREEN MONITOR. WOULD WIDESCREEN GIVE MORE EMMERSION IN THE FLYING? OPINIONS PLEASE.
  10. H.J.Gelsthorpe

    New RC-CAM Project: Bit-Switch

    HI Mr RC CAM Thanks for a great project, was it written in assembler or Basic?. I have a limited experience in Proton developement suite (basic compiler and IDE) As i have only used 16f and 18f devices i was curious and looked to see if my compiler supported 10f series which it does. Can you use any of the 10f series as some only have half the ram?. Any chance to see the source code as a learning oportunity? if the oscal is wiped / overwritten does that render the device useless?
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