27-03-2020, 07:45 AM
A positive - if you can it positive - side effect of the global 'lockdown' due to COVID-19 is that the FT8 frequencies on HF are busy. And I mean busy.
The bands are "abuzz" (pun intended) with FT8 signals at all times of the day and night. Every time I turn the gear on, there are stations there to be worked on FT8.
The other day I worked US and JA stations on 15M (21MHz) where previously I had heard/worked almost nothing on FT8.
The 7 MHz, 10 MHz, 14 MHz and 18 MHz bands almost always have propagation somewhere around the globe and trying to work that station with a received SNR of -15 or lower is an interesting challenge. Success is determined by how much QRM the other end is suffering while we lucky ones in VK have it relatively easy with our low AR population density and distance separation from other countries.
If one reads deep enough in the FT8/digital literature, it suggests that you set the AGC in your transceiver to OFF for these modes - and it does make a difference to your success. If there are other strong VK or ZL stations transmitting during your 15 second receive period, the weaker stations tend to disappear when AGC is ON. AGC OFF solves the problem. Just turn down the audio volume so you don't hear the audio overload effects.
It took a while for me to find how to set AGC off in my Icom IC-7400 but my three available AGC settings are now Fast, Off, and Slow instead of Fast, Medium, Slow. Read your user manual to find out how to do it for your model radio. It does make a difference. Fast for SSB, Off for digital, and I never seem to need Slow these days.
The bands are "abuzz" (pun intended) with FT8 signals at all times of the day and night. Every time I turn the gear on, there are stations there to be worked on FT8.
The other day I worked US and JA stations on 15M (21MHz) where previously I had heard/worked almost nothing on FT8.
The 7 MHz, 10 MHz, 14 MHz and 18 MHz bands almost always have propagation somewhere around the globe and trying to work that station with a received SNR of -15 or lower is an interesting challenge. Success is determined by how much QRM the other end is suffering while we lucky ones in VK have it relatively easy with our low AR population density and distance separation from other countries.
If one reads deep enough in the FT8/digital literature, it suggests that you set the AGC in your transceiver to OFF for these modes - and it does make a difference to your success. If there are other strong VK or ZL stations transmitting during your 15 second receive period, the weaker stations tend to disappear when AGC is ON. AGC OFF solves the problem. Just turn down the audio volume so you don't hear the audio overload effects.
It took a while for me to find how to set AGC off in my Icom IC-7400 but my three available AGC settings are now Fast, Off, and Slow instead of Fast, Medium, Slow. Read your user manual to find out how to do it for your model radio. It does make a difference. Fast for SSB, Off for digital, and I never seem to need Slow these days.
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.
