Reveries of a radio amateur

A very interesting mode in ham radio is SSTV and more interesting is the SSTV from ISS - the International Space Station ! Receiving the images from ISS is pretty simple . However many hams have some problems recording SSTV audio and decoding them using MMSSTV . My ham friends like OM Ramesh VU3RGB , OM Sulaiman VU3SMQ and OM Dhanesh VU3DHN encouraged me to make a blog post describing the various steps involved . 1) The first step is simple . Just tune to 145.800MHz in your VHF receiver and record the audio using some device like your smartphone,holding it near to your rig .It is better to use SDRs like RTLSDR to record audio using a computer. However my shack PC is QRT now , so ,I can't use SDR . Anyway be sure to use some excellent satellite tracking software like the Hamsatdroid (Android) or Orbitron (Windows) to guide you in tracking the ISS . 2) After recording , copy the recorded .amr file to your PC from phone . Use some tool to convert the amr to wav file . One excellen...

Getting into HF is easy and challenging simultaneously for modern homebrewers ! The difficulty lies with the fact that almost all modern ham HF QSOs occur in SSB and homebrewing SSB rigs is a bit tricky . However it is easy to get a large amount of resource from internet regarding the various transceiver circuits , test gigs etc . 40m (7MHz)  is a ham band that is still very active . However all my attempts to make a rig for this band failed due to VFO problems. Browsing the web one of the circuits that grabbed my attention is an old one - Doubler VFO by VU2ITI - OM Mani .( See here  www.qsl.net/vu2msy/homebrew/Ceramic_Resonator_VFO_VU2ITI.pdf )   It a great circuit and the concept is beautiful . Make a ~3.5MHz sine wave , use a multiplier (a nonlinear circuit) , get a 7Mhz output ( and perhaps some undesired harmonics Thanks to OM Joseph Fourier , HI !) . This sounded  beautiful as 3.58MHz ceramic resonators are available in plenty  in my hometown ( Payy...