Thank you. I was reading the technical manual of the RA17 and was nonplussed why there are 2 extra IF stages, and why the LO for the second IF was coming (indirectly) from the LO for the first IF. I made lots of notes for different frequencies being received to try to figure the design rationale. Your video shows the WHY for this design. Excellent.
Thank you for a superb presentation! I brought home a RA-17D yesterday (traded from a ham neighbor) and this video has given me a real appreciation of this history and technology behind this receiver and the Racal name...!
Thanks Brian. Congratulations with your new radio. The RA17 is one of the best analogue receivers from that period of time. But be careful, as stated in my videos, the quality is for 95 percent defined by the filters. Unfortunately, these are tuneable for anyone how things he has the knowledge to do so. And that’s not so, you need a specialist for that with at least a spectrum analyzer. Sometimes the tubes are not 100 percent en replacing them will make things more sensitive. If everything is ok, the receiver will easily be as good as a (short wave) modern (SDR) transceiver / receiver!
@@TheoFaber Hi Theo, very nice to meet you. I am brian kn4r, I tried to look you up on qrz.com but no info found. I am briankn4r AT gmail.com, pse email me if you would... Do you know Anton PA0AST?
@@brianharrison105 send you mail to your gmail acc. Do not know, why qrz.com has no recollection of my call. Put it there, but several Hams share your experience.
Hey Pascal ... It’s not the first mixer! The incoming antenna signal is mixed with 40 to 70 MHz first oscillator, like a ordinary heterodyne receiver. So there is no problem. You are right in your fear that all those signals inside the radio will interfere somehow. But all is well screened and as stated, the antenna signal is mixed to the first IF of 40MHz. The following filter is of extreme quality by coupling 8 high q coils thru air (not physically connected). Of all those harmonics only a 39MHz component is later used in the system. That signal is also cleaned up by a second-high q filter tuned on 39MHz. Those two filters form the centre of a Wadley receiver. By mistuning those filters, a Wadley (Racal) is useless…!
Excellent Theo.... I think the National Hro 500 takes the idea of the harmonic generator to feed the Master oscillator ( ganged Capacitor tuning ) in the Hro 500... you did not talk about the excellent preselection and audio circuits that set these old tube radios apart from NOW NEW top dollar receivers.. Thanks for share.
Thanks for the great vid Theo! I have a mint RA17 and it is one of my favourite radios. I also have an FRG7, SSR1, XCR-30 and DX 302. I would love to see more of that digital RA17 you have there. I hope you are planning a full video on it. Scotty
Thanks .... I also like the RA17 and accessories, great product (1953!). I have made a complete story, about this in a artikel, but alas in Dutch! My 17L/D remake, was fun to create / build. Only with transistors and fet's and exactly to the design of mr Wadley. The result was an very sensitive (0,2uV for 10db s/n) receiver. Hoop to publish this story in a separate film.
It’s not the first mixer! The incoming antenna signal is mixed with 40 to 70 MHz first oscillator, like a ordinary heterodyne receiver. So there is no problem. You are right in your fear that all those signals inside the radio will interfere somehow. But all is well screened and as stated, the antenna signal is mixed to the first IF of 40MHz. The following filter is of extreme quality by coupling 8 high q coils thru air (not physically connected). Of all those harmonics only a 39MHz component is later used in the system. That signal is also cleaned up by a second-high q filter tuned on 39MHz. Those two filters form the centre of a Wadley receiver. By mistuning those filters, a Wadley (Racal) is useless…!
Theo. That was brilliant, thank you. Very well presented, explained superbly and professionally done.
Thanks Trystan, for your nice words...
Thank you. I was reading the technical manual of the RA17 and was nonplussed why there are 2 extra IF stages, and why the LO for the second IF was coming (indirectly) from the LO for the first IF. I made lots of notes for different frequencies being received to try to figure the design rationale. Your video shows the WHY for this design. Excellent.
Lekker Theo! Liefde voor de zaak!
Dank je, Theo.
I remember listening to Radio Nederland's DX Jukebox on a Barlow Wadley.
Lovely radio; lovely station-greatly missed.
Thanks Needle (are you as sharp?) Radio Nederlands, the way you spel, make me think there is some Dutch in you. Eny way, nice weekend...
I would have liked a discription of the Performance and the user experiance: Ease of use,
annoying features etc. experian
Thank you for a superb presentation! I brought home a RA-17D yesterday (traded from a ham neighbor) and this video has given me a real appreciation of this history and technology behind this receiver and the Racal name...!
Thanks Brian. Congratulations with your new radio. The RA17 is one of the best analogue receivers from that period of time. But be careful, as stated in my videos, the quality is for 95 percent defined by the filters. Unfortunately, these are tuneable for anyone how things he has the knowledge to do so. And that’s not so, you need a specialist for that with at least a spectrum analyzer. Sometimes the tubes are not 100 percent en replacing them will make things more sensitive. If everything is ok, the receiver will easily be as good as a (short wave) modern (SDR) transceiver / receiver!
@@TheoFaber Hi Theo, very nice to meet you. I am brian kn4r, I tried to look you up on qrz.com but no info found. I am briankn4r AT gmail.com, pse email me if you would... Do you know Anton PA0AST?
@@brianharrison105 send you mail to your gmail acc. Do not know, why qrz.com has no recollection of my call. Put it there, but several Hams share your experience.
Very informative!! Thank you!!
Hey Pascal ... It’s not the first mixer! The incoming antenna signal is mixed with 40 to 70 MHz first oscillator, like a ordinary heterodyne receiver. So there is no problem. You are right in your fear that all those signals inside the radio will interfere somehow. But all is well screened and as stated, the antenna signal is mixed to the first IF of 40MHz. The following filter is of extreme quality by coupling 8 high q coils thru air (not physically connected). Of all those harmonics only a 39MHz component is later used in the system. That signal is also cleaned up by a second-high q filter tuned on 39MHz. Those two filters form the centre of a Wadley receiver. By mistuning those filters, a Wadley (Racal) is useless…!
Excellent Theo.... I think the National Hro 500 takes the idea of the harmonic generator to feed the Master oscillator ( ganged Capacitor tuning ) in the Hro 500... you did not talk about the excellent preselection and audio circuits that set these old tube radios apart from NOW NEW top dollar receivers.. Thanks for share.
Beatiful!!!
Thanks for the great vid Theo! I have a mint RA17 and it is one of my favourite radios. I also have an FRG7, SSR1, XCR-30 and DX 302. I would love to see more of that digital RA17 you have there. I hope you are planning a full video on it. Scotty
Thanks .... I also like the RA17 and accessories, great product (1953!). I have made a complete story, about this in a artikel, but alas in Dutch! My 17L/D remake, was fun to create / build. Only with transistors and fet's and exactly to the design of mr Wadley. The result was an very sensitive (0,2uV for 10db s/n) receiver. Hoop to publish this story in a separate film.
Thanks again Theo. I look forward to the film. Hopefully you can enable auto translated subtitles on the upload. Scotty.
Theo, with so many harmonics on the first mixer i would expect it to go haywire.
How is that prevented ?
It’s not the first mixer! The incoming antenna signal is mixed with 40 to 70 MHz first oscillator, like a ordinary heterodyne receiver. So there is no problem. You are right in your fear that all those signals inside the radio will interfere somehow. But all is well screened and as stated, the antenna signal is mixed to the first IF of 40MHz. The following filter is of extreme quality by coupling 8 high q coils thru air (not physically connected). Of all those harmonics only a 39MHz component is later used in the system. That signal is also cleaned up by a second-high q filter tuned on 39MHz. Those two filters form the centre of a Wadley receiver. By mistuning those filters, a Wadley (Racal) is useless…!
Nice presentation! Thanks for sharing.
Perfectly explained :-)
thanks!
Very interesting