28-02-2019, 11:23 AM
Ron
Your post made me start thinking.. and do a little researching. I don't have access to the Drew Diamond articles so can't comment on that approach.
While a little old now, the FAT5 project makes for interesting reading : http://www.shortwaveradio.co.uk/fat5_may2010.htm
Even more interesting was the article on the PWM-mode modulator to achieve AM. http://www.shortwaveradio.co.uk/puwma%20draft4.pdf
There are probably other sources in lieu of VFO or crystal stabilisation, eg a DDS module from VK5TM : https://www.ahrdf.net/forum/thread-646-p...ml#pid2658 and http://www.vk5tm.com/homebrew/dds_vfo_8/dds_8.php
A thought did cross my mind about this project though : if you could find an old HF marine transceiver that worked down on 2MHz, that could supply you with most of the parts you would need to re-homebrew with. The tuning capacitors etc, maybe the output LPF parts, modulation arrangements, etc.., all might be suitable particularly if you used an old-technology approach.
I have to admit to not having homebrewed a HF transmitter in years and then it was a single-band 20M SSB transceiving device using 4 x FT243 style crystals in a homebrew crystal filter at around 5MHz, another as the carrier injection crystal. I don't have the whole device left but I did retain the crystal filter - it's in the parts junkbox. I have certainly done VHF / UHF / microwave homebrewing and even test gear for HF, but no straight transmitters. I don't have any plans for 600M and 2200M gear either so no homebrewing for there either.
Your post made me start thinking.. and do a little researching. I don't have access to the Drew Diamond articles so can't comment on that approach.
While a little old now, the FAT5 project makes for interesting reading : http://www.shortwaveradio.co.uk/fat5_may2010.htm
Even more interesting was the article on the PWM-mode modulator to achieve AM. http://www.shortwaveradio.co.uk/puwma%20draft4.pdf
There are probably other sources in lieu of VFO or crystal stabilisation, eg a DDS module from VK5TM : https://www.ahrdf.net/forum/thread-646-p...ml#pid2658 and http://www.vk5tm.com/homebrew/dds_vfo_8/dds_8.php
A thought did cross my mind about this project though : if you could find an old HF marine transceiver that worked down on 2MHz, that could supply you with most of the parts you would need to re-homebrew with. The tuning capacitors etc, maybe the output LPF parts, modulation arrangements, etc.., all might be suitable particularly if you used an old-technology approach.
I have to admit to not having homebrewed a HF transmitter in years and then it was a single-band 20M SSB transceiving device using 4 x FT243 style crystals in a homebrew crystal filter at around 5MHz, another as the carrier injection crystal. I don't have the whole device left but I did retain the crystal filter - it's in the parts junkbox. I have certainly done VHF / UHF / microwave homebrewing and even test gear for HF, but no straight transmitters. I don't have any plans for 600M and 2200M gear either so no homebrewing for there either.
Doug VK4ADC @ QG62LG51
http://www.vk4adc.com
This Forum is only going to be as interesting as the posts it contains.
If you have a comment or question, post it as it may trigger or answer the query in someone else's mind.
http://www.vk4adc.com
This Forum is only going to be as interesting as the posts it contains.
If you have a comment or question, post it as it may trigger or answer the query in someone else's mind.