EMRFD Message Archive 12036
Message Date From Subject 12036 2015-12-18 13:43:17 lawrence_joy PA3AKE Holy Grail RCVR Has anybody built one of these or is attempting to build one? Any pros, cons, or tidbits?
Thanks--9V1MI/WN8P, Larry
12037 2015-12-18 14:47:49 Lasse Moell Re: PA3AKE Holy Grail RCVR I do have a partial kit that I should start to assemble, any day now :)What is lacking is the realization of a matching LO!Now technology marches on, and I do have some ideas of using parts of the receiver mated with a SDR to get the best of both worlds...Still a very ambitious project,and should provide hours of fun of tinkering. BTW I do hear PA3AKE on 7 MHz every now and then working DX!73Lasse SM5GLC18 december 2015 22:41:53 +01:00, skrev lawrence_joy@yahoo.com [emrfd]:
Has anybody built one of these or is attempting to build one? Any pros, cons, or tidbits?
Thanks--9V1MI/WN8P, Larry
12038 2015-12-18 19:13:42 K5ESS Re: PA3AKE Holy Grail RCVR Can’t seem to find anything on the web about this receiver. Sounds interesting. Can someone point me to where I can find information on it?
Thanks,
Mike K5ESS
12039 2015-12-18 19:43:47 Dan Rae Re: PA3AKE Holy Grail RCVR 12040 2015-12-18 22:01:56 farhanbox@gmail.c... Re: PA3AKE Holy Grail RCVR 12041 2015-12-19 05:08:31 Steve Dick Re: PA3AKE Holy Grail RCVR I believe you are referring to this high performance up-conversion receiver in the July/August 2013 issue of QEX magazine, called the HF7070. Quite an interesting read. There was also a follow-up articles:“A High Performance 45 MHz IF amplifier for an upconversion HF/LF Receiver” by Colin Horrabin, G3SBI, May/June 2015 QEX magazine“Some thoughts on developing high performance VHF oscillators” by Dr. Ulrich Rohde, N1UL” Nov/Dec 2015 QEX where he comments on the oscillator design in the HF7070.I am attempting to (slowly) build a version of the HF7070. My main problem is that I have a lack of test equipment to build it. I am building up a “Poor ham’s Scalar Network Analyzer” or PHSNA, a return loss bridge, crystal test fixture, attenuators, tw RF generators, combiner, etc. I will post when I have more info to post to the group. It will not have as good performance, as it will use lower performance components, but will still have very good performance.Some changes from the described design include:- RF front bandpass filters based on 4 pole butterworth filters using ELSIE and switched with Perigrine PE4250 switches. Optimized for ham bands but continuous coverage. Design done.- push pull Norton RF preamp from Clifton Labs driving a splitter – one path for the main receiver, another path for wideband SDR output spigot.- Switchable input attenuators- the 45-75MHz local oscillator based on an SI570 or some other single chip integrated device and a divide by 2 flip flop squarer- the second local oscillator based on a single chip fixed frequency device and a divide by 2 flip flop squarer- “Kiss” mixers based on the article by Chris Trask/N7ZYW “Mixer Musings and the KISS Mixer”- A pair of hybrid connected 4 pole 6 KHz 45MHz Vectron crystal filters from Vectron that I scored on EBAY that have very good specs. I will select two closely matched ones from a group of them- PHA1+ MMIC low noise high dynamic range preamp following the 45 MHz hybrid connected filters- Amplifier following the second mixer TBD- Digital downconversion and signal processing performed in a ST Microelectronics STM32F746G-DISCO for about $60.00. High performance floating point processor and large touch screen display built-in.- 8 watt low distortion STM class AB audio output chip used in car radiosThis is a challenging effort but I’m attempting it.Regards, “Digital Steve”, K1RF12042 2015-12-19 05:59:56 Lasse Moell Re: PA3AKE Holy Grail RCVR Wow Steve!You seem to undertake quite a projekt! Wish you good luck, and hopfully will bring this mammoth undertaking into harbour :)Now PA3AKE, did shoot for a single conversion radio that aimed for the best. Period.Please read all about it on this link:It do have information on the 7070 up-conversion, but as you will see it is quite different.One thing that is missing in PA3AKE-design is the finalized LO... he looked at various topologies, and found out some design flaws made by Analog Devices in their state-of-the-art DDS chip. Now I believe that newer chips has this corrected and my fit the bill. Using a Si570 may not give the perfomance you wanted...Season Greetings/Lasse SM5GLC19 december 2015 14:08:26 +01:00, skrev Steve Dick sbdick@optonline.net [emrfd]:
I believe you are referring to this high performance up-conversion receiver in the July/August 2013 issue of QEX magazine, called the HF7070. Quite an interesting read. There was also a follow-up articles:“A High Performance 45 MHz IF amplifier for an upconversion HF/LF Receiver” by Colin Horrabin, G3SBI, May/June 2015 QEX magazine“Some thoughts on developing high performance VHF oscillators” by Dr. Ulrich Rohde, N1UL” Nov/Dec 2015 QEX where he comments on the oscillator design in the HF7070.I am attempting to (slowly) build a version of the HF7070. My main problem is that I have a lack of test equipment to build it. I am building up a “Poor ham’s Scalar Network Analyzer” or PHSNA, a return loss bridge, crystal test fixture, attenuators, tw RF generators, combiner, etc. I will post when I have more info to post to the group. It will not have as good performance, as it will use lower performance components, but will still have very good performance.Some changes from the described design include:- RF front bandpass filters based on 4 pole butterworth filters using ELSIE and switched with Perigrine PE4250 switches. Optimized for ham bands but continuous coverage. Design done.- push pull Norton RF preamp from Clifton Labs driving a splitter – one path for the main receiver, another path for wideband SDR output spigot.- Switchable input attenuators- the 45-75MHz local oscillator based on an SI570 or some other single chip integrated device and a divide by 2 flip flop squarer- the second local oscillator based on a single chip fixed frequency device and a divide by 2 flip flop squarer- “Kiss” mixers based on the article by Chris Trask/N7ZYW “Mixer Musings and the KISS Mixer”- A pair of hybrid connected 4 pole 6 KHz 45MHz Vectron crystal filters from Vectron that I scored on EBAY that have very good specs. I will select two closely matched ones from a group of them- PHA1+ MMIC low noise high dynamic range preamp following the 45 MHz hybrid connected filters- Amplifier following the second mixer TBD- Digital downconversion and signal processing performed in a ST Microelectronics STM32F746G-DISCO for about $60.00. High performance floating point processor and large touch screen display built-in.- 8 watt low distorti12043 2015-12-19 07:27:02 Bill Carver Re: PA3AKE Holy Grail RCVR I've built the front end. It works. Lots of work winding coils but the PCBs are superb. The DDS boards are a work of (engineering) art, superb layout.
Getting the super-IMD 9 MHz xtals might be difficult unless there is another group buy from QT.
W7AAZ
12044 2015-12-19 07:28:39 Bill Carver Re: PA3AKE Holy Grail RCVR Lasse, have you built Martein's AD9910/12 DDS board?
Bill W7AAZ
12048 2015-12-19 11:48:35 Lasse Moell Re: PA3AKE Holy Grail RCVR Bill,did not even know it exsisted! Thought he given up12050 2015-12-19 12:16:35 Bill Carver Re: PA3AKE Holy Grail RCVR 12052 2015-12-20 03:27:28 Lasse Moell Re: PA3AKE Holy Grail RCVR Bill,guess I'm getting older. Once seeing these pages I do remember reading about it few years ago.. But it all slipped my mind. Very interesting and inspiring for sure. Wish I had a bit more spare time to do stuff like that. Guess I have to QRX for retirement, another ten years or so :)Cheers and Season Greetings to everone on the list./Lasse SM5GLCIs it not public, posted with his other receiver material??? Whew, thought I was losing my mind!That text describes a DDS journey. Although for a dedicated traveller there is never a final destination. But sometimes you find the best place is not the latest. In that link you will find an AD9910 LO there and I believe that is the best today. Martein's AD9910 board is done right: analog and digital grounds are done properly, bypassing is correct, voltage regulation system is lower noise, and the output filtering geometry does not let things to leak around the filters. Martein found 1/f noise in the AD9910/12 design that compromises its phase noise performance. ADI corrected that in the AD9914 but the loss of two bits in the DAC increases the discrete spurious signals: they are shown in the data sheet. It seems to me the AD9910 is the best tradeoff for an HF LO at this time.Bill W7AAZ12068 2015-12-21 18:48:55 lawrence_joy Re: PA3AKE Holy Grail RCVR Lasse,What constitutes your partial kit? Do you have some or all of the PCBs? Crystals for the filters? Other components? Chassis? One thing the Holy Grail receiver lacks is a noise blanker, which I sent an e-mail to Martein about, and got an answer back several years back when I was still living in Singapore. The other receivers (transceivers) that have appeared in QEX and QST, like the one by Markus Hansen, VE7CA, and Cornell Drentea, KW7CD, have this circuitry. What would really be nice is the Gerber files for the PCBs plus PCB fabrication information.73 de Larry12069 2015-12-21 18:49:10 lawrence_joy Re: PA3AKE Holy Grail RCVR Bill,Where did you get your PCBs?73 de Larry12070 2015-12-21 18:49:36 lawrence_joy Re: PA3AKE Holy Grail RCVR Bill,Thanks for that tidbit of information about the AD9910 versus the AD9914. That is the kind of information I am on the hunt for.73 de Larry12072 2015-12-21 21:24:19 Bill Carver Re: PA3AKE Holy Grail RCVR Martein has had group buys over the years. I bought the high intercept 9 MHz "QT" xtals and PC boards. He had some mechanical pieces to put subassemblies in, but I did that myself (I have fabrication tools for chassis/panels, etc). I don't know what the status is now.
Bill
12073 2015-12-21 21:30:14 Bill Carver Re: PA3AKE Holy Grail RCVR All that info is from Martein, and Colin Horrabin, G3SBI. I watched as Martein found the sources of phase noise, the final one finding a noise generator inside the AD9910/AD9912 itself! Analog Devices removed them from AD9914 and it's quieter. But with two fewer bits it has worse discrete spurs. As Martein says, although the phase noise of the AD9910 could/should have been lower, they are still the best that's available.
Bill
12075 2015-12-22 06:20:09 Lasse Moell Re: PA3AKE Holy Grail RCVR Larry,I do have the PCB's for filter, mixer and IF... and did buy the inductors and caps from Italy. Oh yes do have tin boxes for the PCB. So no full kit... I do intend to start winding toroid coils any day :) Somehow life got inbetween and I have been quite busy with dayjob and such for the past year.CheersLasse SM5GLC22 december 2015 02:06:32 +01:00, skrev lawrence_joy@yahoo.com [emrfd]: Lasse,
What constitutes your partial kit? Do you have some or all of the PCBs? Crystals for the filters? Other components? Chassis? One thing the Holy Grail receiver lacks is a noise blanker, which I sent an e-mail to Martein about, and got an answer back several years back when I was still living in Singapore. The other receivers (transceivers) that have appeared in QEX and QST, like the one by Markus Hansen, VE7CA, and Cornell Drentea, KW7CD, have this circuitry. What would really be nice is the Gerber files for the PCBs plus PCB fabrication information.73 de Larry