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#1
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Dale W4OP,
Dale, I believe you posted an e-mail and a link to QRP-L a while back to show your receiver. Should have said this before but better late than never. Nice job. If I remember correctly you used a basic 160M receiver with multiple front end convertors. Also I believe you used blue backlighting? Don, K5UOS |
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#2
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wrote in message oups.com... Dale W4OP, Dale, I believe you posted an e-mail and a link to QRP-L a while back to show your receiver. Should have said this before but better late than never. Nice job. If I remember correctly you used a basic 160M receiver with multiple front end convertors. Also I believe you used blue backlighting? Don, K5UOS Hi Don, Thanks for the kind words. The receiver is based on W7ZOI's Progressive RX from the late 80's. To Wes's excellent design I added, S meter AM detection LM386 for loudspeaker w/ tone control audio notch filter Homebrew 5/2.5/.5 xtal filters fast/slow/off AGC 80M RX with xtal controlled converters for 160/49/40/20/15/10ABC The VFO drifts a little over 150Hz in the 1st 5 minutes then settles down to +/- 20Hz in a 5 minute period. Wonderful sound and gets more use than the PRO II 73, Dale W4OP |
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#3
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Well Dale it looks very nice and obviously works well too. I thought I
remembered you saying the Progressive Receiver. I am glad I had a chance to compliment you. Since the subject was the Eddiestone dial I expect that was probably a chore to install. I usually build homebrew dial chord and drum mechanisms and more recently use the flange type Jackson Brothers and Oren Elliot drives. I just figured out a way to make custom dial plates. Probably an old idea but new to me. I just finished a 40M receiver for a SSB transceiver. I thought about using a small blank CD for the dial plate. What I ended up doing was getting a piece of brass sheet from ACE Hardware and using a 2 1/4" hole saw (my chassis panel is 3") I cut a round disc. I had a small amount of deburring to do but the brass is way tougher than aluminum and a simple file removed the burrs. The 3/8" drill bit also provided a true center for the dial plate. I polished it with super fine auto rubbing compound. I ended up with a nice dial plate. I need to mount it to a small shaft section of a vernier capacitor from Ocean State Electronics. I took a shaft coupler, the type with removable couplings on both sides, and using very tiny scews mounted this removable portion of the coupling to the plate. Its hard to describe. But I am pleased with myself as I a mechanically weak. This is a good method for making custom dial plates. I had to use a good chord type drill as my cordless was getting warm. I also mounted the plate for drilling using two wood screws and fastening the uncut plate to a scrap 2 x 4 by drilling holes slightly above and below my cut. Now I gotta figure out how to mark the plate. Well maybe I will catch you on the air sometime Dale. K5UOS Dale Parfitt wrote: wrote in message oups.com... Dale W4OP, Dale, I believe you posted an e-mail and a link to QRP-L a while back to show your receiver. Should have said this before but better late than never. Nice job. If I remember correctly you used a basic 160M receiver with multiple front end convertors. Also I believe you used blue backlighting? Don, K5UOS Hi Don, Thanks for the kind words. The receiver is based on W7ZOI's Progressive RX from the late 80's. To Wes's excellent design I added, S meter AM detection LM386 for loudspeaker w/ tone control audio notch filter Homebrew 5/2.5/.5 xtal filters fast/slow/off AGC 80M RX with xtal controlled converters for 160/49/40/20/15/10ABC The VFO drifts a little over 150Hz in the 1st 5 minutes then settles down to +/- 20Hz in a 5 minute period. Wonderful sound and gets more use than the PRO II 73, Dale W4OP |
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#5
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Hi Don and Ted,
While it has been over a year now since I did the VFO- I too had some difficulties with the QST values. In talking w/ W7ZOI, Wes indicated that some errors had worked their way into the design over the years. One was on the audio amp- values I had caused severe rolloff below about 2KHz- making SSB very tinny. The other was on the VFO. Because of the Eddystone dial, I wished to make the VFO as linear as possible- book values led to a highly non linear scale. I do not recall exactly what I did- although I played with the math for a long time- to lienarize it- but I would trust your calcs. At some point I will open her up again as I want to buffer the VFO and tap off for a TX VFO- the plan is to build a Drake style reciter for the RX- and at that time will better document the changes I made. Dale W4OP |
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#6
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Dale & Don,
I haven't had a chance to lash up the components yet, but I checked my spreadsheet using Wes's example on page 4.4. The numbers check out; unfortunately, Wes specifies a value for C3 in the EMRFD example, and in the Progressive Receiver Article, C3 is the unknown; i.e., how much additional capacitance you'd have to add in parallel with the coil to use a specific variable cap in the given configuration. Now that I can see the "C12v" equation in EMRFD, which is not in the QST article, but I've modified my spreadsheet to include it I can check the resonance using the given values for L. Dale, when I looked at your jpg's again yesterday, I noticed that you've modified the receiver internals a lot since I first saw the rig. Since the links I had were to a directory on your commercial site, I'm not sure if you have another site where you described what you did. Early last Spring, I got rid of all my new-fangled ham rigs, like the FT-817 and the not-so-new, but pristine TS-530s and bought an HW-101 and some equipment to restore. Homebrewing and boatanchors is what I'm about now. I did the VFO alignment on the HW-101 and was able to get it within 1kHz, end to end, as indicated on the dial, anyway. That surprised the heck out of me. I've since acquired an LMO from an SB-401 that I'm going to put in a project somewhere along the line. I have a complete set of Heath HFO crystals, and both CW and SSB filters from another source. I might make myself a broadbanded QRP rig out of those. 73, Ted KX4OM On Sun, 02 Apr 2006 02:20:25 GMT, "Dale Parfitt" wrote: Hi Don and Ted, While it has been over a year now since I did the VFO- I too had some difficulties with the QST values. In talking w/ W7ZOI, Wes indicated that some errors had worked their way into the design over the years. One was on the audio amp- values I had caused severe rolloff below about 2KHz- making SSB very tinny. The other was on the VFO. Because of the Eddystone dial, I wished to make the VFO as linear as possible- book values led to a highly non linear scale. I do not recall exactly what I did- although I played with the math for a long time- to lienarize it- but I would trust your calcs. At some point I will open her up again as I want to buffer the VFO and tap off for a TX VFO- the plan is to build a Drake style reciter for the RX- and at that time will better document the changes I made. Dale W4OP |
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#7
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"Ted" wrote in message ... Dale & Don, I haven't had a chance to lash up the components yet, but I checked my spreadsheet using Wes's example on page 4.4. The numbers check out; unfortunately, Wes specifies a value for C3 in the EMRFD example, and in the Progressive Receiver Article, C3 is the unknown; i.e., how much additional capacitance you'd have to add in parallel with the coil to use a specific variable cap in the given configuration. Now that I can see the "C12v" equation in EMRFD, which is not in the QST article, but I've modified my spreadsheet to include it I can check the resonance using the given values for L. Dale, when I looked at your jpg's again yesterday, I noticed that you've modified the receiver internals a lot since I first saw the rig. Since the links I had were to a directory on your commercial site, I'm not sure if you have another site where you described what you did. Early last Spring, I got rid of all my new-fangled ham rigs, like the FT-817 and the not-so-new, but pristine TS-530s and bought an HW-101 and some equipment to restore. Homebrewing and boatanchors is what I'm about now. I did the VFO alignment on the HW-101 and was able to get it within 1kHz, end to end, as indicated on the dial, anyway. That surprised the heck out of me. I've since acquired an LMO from an SB-401 that I'm going to put in a project somewhere along the line. I have a complete set of Heath HFO crystals, and both CW and SSB filters from another source. I might make myself a broadbanded QRP rig out of those. 73, Ted KX4OM Hi Ted, I quickly looked at the VFO schematic in my1994 Handbook that had the PR. I seem to recall in the end I replaced C1 with a short- just eliminating it. Not 100% positive, but think that was what it came down to in order to get good linearity out of my VFO. Dale |
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