Transmitting on the right frequency with direct conversion CW transceivers
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- Опубліковано 24 бер 2017
- A discussion on transmit / receive frequency offsets as they apply to CW direct conversion transceivers. Related video: • Three features every h...
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I love your analog frequency teaching tool! Your explanation is very clear and easily understood. Thanks Peter! I think the tuning set up for the split 40 radio is also very clever and has great benefits for operation.
I like Peter Your movies. They are factually good and you don't act out. I like listening to your substantive arguments. Best wishes from Poland (Europa) . Robert SP5RF.
Why have I missed your channel??
Such a perfectly simple explanation.
I have subbed your channel for a good binge watch later. Thank you!
Excellent explanation!
Always great content from a truly dedicated Ham and Elmer.
Thanks Peter & 73… 😊
Thanks Peter, I knew you would have a answer that made sense. Great presentation, and thanks for all of the videos. I'm sure I am not the only one watching. I've been a ham sense 1998, I decided I wanted to learn how to build my own rig. I've been following you and W1FB for a couple of years now. I've been mainly working on various circuits, loving it too. Now I have to polish up on my CW, I've been slack on getting on the air. Anyway, you have a talent for explaining things, making sense of it all, I also like the fact that you include schematics and explain them. My first build will be a CW Rig, then I'm going to tackle your Phasing SSB Radio, And the one from W1FB. Again thank you for the video, thanks for all of the instruction. 73's Peter
PS. Just so you know, I did buy both of your E-books. I keep them on my cell phone for when I'm on the go
Clean and concise. Thank you!
What a creative and lucid way to explain! Simply outstanding. Thanks. De VU2RJV Raj
Thanks OM Peter. Great idea and lucid explanation. 73 de vu2dny, Deena.
good useage of overlays to show whats going on kg6mn
Hello Peter. Your presentation style and content are wonderful. I find myself hurredly opening your videos as soon as they are published! Thank you for your contribution to our fantastic hobby! As an aside. I can easily comment on your videos in public when I am at my desktop computer. However when I view your videos with my iPhone I do not appear to be able to comment. Is this an iPhone setting I wonder? I note your comments that sometimes you receive questions and comments via personal emails. Perhaps this is the reason why? 72 Dick N4HAY
Thanks Richard. Not sure about IPhone settings but I sometimes have difficulties in commenting on UA-cam from my home computer. Eg error messages eg 'comment failed to post'. Seems to be a common issue but normally fixable by trying again later.
Good video 73
Helpful, TY!
Really great video but all I actually needed was 800Hz, thanks though!
Peter: I'm having trouble setting up a frequency offset on a 40 meter DC transceiver. 1 pf moves the VFO 17 kc! I only need it to move 700 Hz. Any thoughts on a circuit that will move the freq the desired SMALL amount? I may have to resort to your two VFO with a spot switch... 73 Bill N2CQR
Bill - Try series and parallel capacitors. Eg something like a 20 pF trimmer in parallel with a 220 pF capacitor will give a range of 220 - 240pF. Then put that in series with a low value capacitor - say 10pF. I haven't done the maths but you will get a very small variation in total capacitance.
Other more common options include some sort of diode circuit using almost any type of diode (which can vary capacitance when DC is applied). Then you have a fixed voltage divider on transmit but then on receive have a potentiometer to allow some fine tuning +/- your centre frequency. That gives you a variable offset which is handy for DC transceivers. Solid State Design probably has circuits for that.
@@vk3ye It is much harder than it seems. My transmitter VFO is all set up and very stable, but if I add 10 pf, the frequency changes by 170 kHz! So 1 pf would move the VFO about 17 kHz. Way too much. I need to move it by 700 Hz! Even the switching arrangements (diodes, relays) add capacitance. I've tried with a "gimmick" but it is difficult.
@@williamrmeara2162 Use a smaller inductor. Then you have more capacitance to play around with. Or reduce C values in the oscillator. Then use diodes as varactors to vary the frequency slightly. Switch in a fixed voltage divider on Tx and a pot for RIT on Rx. All explained in Solid State Design.