15-06-2017, 07:33 PM
Nothing heard !!
I do have an alternative plan to resolve the issues with the transverter:
I have since bought a couple of SMD-style SAW filters from Mark at Minikits (arrived yesterday) and have laid out a small adapter PCB since I don't want to trash the entire transverter PCB. The plan is to etch up a couple of these PCBs, mount MMIC bias resistors as needed plus DC blocking caps to all I/O pins of the SAWs. The adapter PCB is then soldered on the top side of the main PCB with wire-throughs in the same positions as the original 5HW series helical filter pins. The SAWs are centred on 1316 MHz but the 50 MHz total bandpass characteristics includes the 1296 region.
http://www.minikits.com.au/components/pa...rs/TA0933A
By the way, in an email exchange with Mark he advises there is a new 1296 project that uses SAW filters:
"I already have done the 23cm Transverter design but not built one it uses the same PCB as the new 2.4GHz Transverter. We have a new low noise PLL soon to be released to do the 1156MHz, or the new multiplier can be used.
EME227 transverter series
EME228 multiplier board
"
Sidenote: The TA1090EC ADS-B 1090MHz SAW Filter from Minikits would also suit replacement of the existing LO helical resonator for a 144-148MHz IF use.... provided an adapter PCB was used there too.
I am hopeful that I will get the adapter PCBs created over the next few days, parts added, and fitted to the transverter PCB, and fired up. Hopefully my existing 20dB loss will disappear !!!
73 Doug VK4ADC
I do have an alternative plan to resolve the issues with the transverter:
I have since bought a couple of SMD-style SAW filters from Mark at Minikits (arrived yesterday) and have laid out a small adapter PCB since I don't want to trash the entire transverter PCB. The plan is to etch up a couple of these PCBs, mount MMIC bias resistors as needed plus DC blocking caps to all I/O pins of the SAWs. The adapter PCB is then soldered on the top side of the main PCB with wire-throughs in the same positions as the original 5HW series helical filter pins. The SAWs are centred on 1316 MHz but the 50 MHz total bandpass characteristics includes the 1296 region.
http://www.minikits.com.au/components/pa...rs/TA0933A
By the way, in an email exchange with Mark he advises there is a new 1296 project that uses SAW filters:
"I already have done the 23cm Transverter design but not built one it uses the same PCB as the new 2.4GHz Transverter. We have a new low noise PLL soon to be released to do the 1156MHz, or the new multiplier can be used.
EME227 transverter series
EME228 multiplier board
"
Sidenote: The TA1090EC ADS-B 1090MHz SAW Filter from Minikits would also suit replacement of the existing LO helical resonator for a 144-148MHz IF use.... provided an adapter PCB was used there too.
I am hopeful that I will get the adapter PCBs created over the next few days, parts added, and fitted to the transverter PCB, and fired up. Hopefully my existing 20dB loss will disappear !!!
73 Doug VK4ADC
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.