Re: Re: LF: Re: My transmit converter description

[Dimitrios Tsifakis <dtsifakis@gmail.com>]

Hi Eike,

2013/2/9 Eike Katzera <dl3ike@web.de>:
> Hi Dimitris,
> have you ever thought about using an Class-D-audio-Amp as a powersupply for
> the Class-E-RF-Amp?
> Let the audi-amp follow the rf-envelope an the rf-amp follow the frequency.
> Is that accurate enough to work as an linear-rf-amp for digi-modes?

I think others have actually done this, isn't this the "envelop
elimination and restoration" technique? In any case, my answer is that
I don't know :-) I am just a beginner and my objective with this
transmit converter was to get on air with the simplest possible device
that will allow the most popular digi modes to be used. The majority
of the popular LF/MF digi modes are indeed non-linear, so not having a
linear amplifier was considered not to be a major disadvantage.


> PS: what are the correct settings in wspr-software for using split mode in
> the transceifer in combination with an transverter to prevent data mismatch
> in the wspr-database? Transceifer RX: 474kHz, TX:10.474kHz

Yes, that is correct. The transceiver is set as you described and the
WSPR software is set to 474 kHz. The T/R switching can be easily
handled by the signals available at the back of the my FT817 (and I
guess most other transceivers) and a simple relay is enough as I use
the miniwhip to receive and the inverded-L to transmit.

73, Dimitris VK1SV