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Questions from a newbie ham (lemmy.ml)

submitted 5 months ago by [email protected] to c/[email protected]

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Right, so this is the situation: I still haven't obtained my license here in Brazil, but I already have a Baofeng DR-1801 HT that can connect to dmr networks. Therefore I haven't transmitted yet. But I'd like to clarify some doubts:

When I get my license, even in C-class in Brazil, I will be allowed access to some frequencies in 40-10m bands. Should I get a low power QRP transceiver (e.g. uSDX) or go for an used rig from known brands?
It's almost impossible to find a transceiver project with a power rating greater than 10w. What would be the difficulty of, say, copylefting the schematics of an ft-7b?
Can I really use a wire thrown over my house (of course, with baluns and stuff) as a monopole antenna or that's just myth?

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[–] [email protected] 0 points 5 months ago* (last edited 5 months ago)

Yes, it's the ratio of how much of the power that you transmit is reflected back towards your rig due to impedence mismatch of antenna <-> radio.

Ideally you want SWR < 2, but for simple voice modes at QRP power, it's not the end of the world if you end up in the 2-3 range. However digital modes need a good SWR because they transmit at 100% duty cycle. If I don't get SWR < 2 for my IC-705 during a digital transmit, the reflected power causes my computer's USB port to reset. At higher powers it could damage my rig or my computer, so it's definitely a thing to avoid.