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Re: Some BCI Filter Notes
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Re: Some BCI Filter Notes
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Two Tinned Tunas x4
I am getting ready to build a pile of Tunas, acquired from QRPme directly and through estate sales, all unbuilt. The first is a retired single band Two Tinned Tunas, now replaced by the EZ Build Version. The 2nd is an original Super Tuna ][ with version not marked, it has the scoring in case you want to put it in a square tin can. Third is a Super Tuna ][+ marked Ver 2. The Fourth is a Super Tuna ][+ marked Ver 4. I have a generous supply of band modules from the last three that might even allow me to have at least 2 xtals per the four bands, 10M included. First, I have 32 separate water tests for CL2 and Nitrates to sample over the next couple of weeks, pumping out all of the iron and other exotic minerals cruising around the mountain cracks in the hand pump wells. It has been raining like cats and dogs day and night here in the central Colorado mountains, so there are no fire bans this month, but the problem is the skidders are snowed in without being able to get a lot of the logs out that would be sending 1096 bundles of firewood to us x 4 or 5 depending on how wet of a summer it is. I will have photos of the 3-band vertical I am building as well as some graphs of the VSWR patterns so the "Little Super Tuna ][+ that could" will be heard outside of the valley surrounded by 14K' peaks on all four sides. Cheers, Davey - KU9L |
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Re: Sudden Storm RX Ver.6
Rex, I find no difference in the receiver performance between running directly off the LIFEPO4 lithium batteries at 13.3 volts or from the buck converter at 12.3 volts, fortunately. Either the SS has excellent ripple filtering or the Buck converter does as well. The SS 7809 only wants to put out 8.8 volts either way, but it is rock solid. The popping noise, once I rule out where it is coming from, is my last hurdle. I turned on and off every appliance and light in the RV with no difference. I even shut off the RV DC converter & disabled my solar controllers, no difference. When I try my vertical antenna outside in the National Forest I will know more. Maybe it is generated from my alien implant & the QRN follows me around, LOL. I am looking forward to the buildathon. When I ordered it I didn't see a second option to have it sent to me, so am crossing my fingers that my fingers did the right thing. Cheers, Davey - KU9L
On Sunday, May 14, 2023 at 10:41:58 PM MDT, Rex Harper <tunacankits@...> wrote:
On 5/12/2023 10:55 AM, David Knapp via
groups.io wrote:
One question: Is the 33pf cap
CzBM on the band module needed or not? The Schematic on Ver. 6
show it and it is on the parts list but wasn't included in the
kit or on the Band Module expansion kit.
Dave, Looking at the schematic, you can see that Cz on the band module
is in the local oscillator circuit along with the crystal and
'pseudo varactor'. Via trial & error, Cz was found to be 33pf
to make the local oscillator run as close to the frequency marked
on QRPme crystals. The 1N4005 is a pretty crappy varactor so the
frequency doesn't swing to far from the crystal. The WWVR, however, does have a real varactor which gives it a better tuning range but no 'CZ' for a 'permanent' minimum offset for the crystal. The various revisions of the WWVR were made to add more varactor diode footprints in order to facilitate sourcing and experimenting. Ver 1 was the original board as produced for the Duke City Hamfest Buildathon. Ver3 added another footprint or 2 and it was the only one I know of that has the missing grounding 'rays' on that center section of circuitry. I will get a document up on the page to show that problem and the fix but Ver3 boards are no longer sent out unless it was a missteak like the one I sent you.... I only send out the original Ver1 boards now until I get and new Ver4 board in house. Budget constraints have prevented me from ordering new Ver4 boards but I will be soon. Sorry for your troubles. I'm glad I could help you resolve the problem and get that Ver3 board up & running. BTW, the Sudden Storm and WWVR receivers are direct conversion receivers using the LM386-3 audio amplifier set for MAX GAIN. Any ripple in the DC supply could show up in the audio output when amplified by 200 or even more for the WWVR circuit. It is always better to run them off battery power unless you have a very good converter. Rex |
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Re: LM-386 Live or Die?
Russell, Both the WWVR and the Sudden Storm receivers performed well enough to receive my 10 MW transmitter into a dummy load next to the receivers. The Sudden Storm sounded really nice and pure of tone, and the WWVR sounded a bit of a heterodyne almost like a two-tone, but it heard my signal clearly. The Sudden Storm was right-on frequency both on 7 & 10 Mhz, the WWVR was about 2 KHz low. Both receivers had the rapid "electric fence pops" that I do not hear on my Penttek TR-35 or is 99% reduced. I can not compare a direct conversion receiver to my Penntek which is pretty darn good for a kit that costs even less than some of the Chinese HF radios.? I could not hear any other stations on my Sudden Storm 40, 30, or 20M. My indoor 1/2~ antenna with Tuna Tuna sucks. With the TR-35, I heard 5-6 CW stations and 2-3 SSB stations but did not have an Xtal to try the Sudden Storm on those frequencies of course. I tried opening a window and snuck out my 44' 30M 1/2~ wire and immediately the campground staff became entangled in it doing their rounds of reading the electric meters, checking the faucets for freezing, and spraying herbicide in these giant 20 acres pea-gravel parking lot they call an RV Park. So I started building an antenna kit I bought six months ago, it is a 3-band vertical for 40, 30, and 20M from QRPGuys which has a couple of toroids and 17 feet of vertical wire wrapped loosely around a 7M carbon-fiber fishing pole. This will be less prone to campground staff tripping over it, but also be transportable to any of our 13 campgrounds in the San Isabel NF that my wife and I run with the aid of our camp hosts. Any wood fence posts will be a good test and since power lines are generally miles away there are fewer opportunities for QRN except when someone is running their generator, but there are hundreds of day-use areas also that have no RVs to make QRN. Anyway, I can then continue running my receiver tests. The biggest challenge is that the audio levels in the headphones are about 20-30 dB too high in many cases. But, I won't mess with the gain until I can get out into the wild blue yonder to hear native signals that will help determine the real audio can levels required and possibly figure out where the "electric fence pops" noise might be coming from if I put the receiver volume higher than zero. My Penntek does not have an automatic receiver mute into from an external source or I would set aside my two tuna receivers and start building my Super Tuna ][+ TX, but my biggest issue is lack of time. Most of our hosts have been arriving the past few days and I am delivering water tanks and installing pump handles getting ready to do the water bacteria tests for the state testing labs. I look forward to our two maintenance men starting this week as well, carrying gold cart batteries for re-install is a PIA, LOL. Attached is the antenna I am building. The toroids are so huge a blind man can build them, LOL. Cheers, Davey - KU9L
On Friday, May 12, 2023 at 09:20:56 AM MDT, Russell Smith via groups.io <n0qlt@...> wrote:
Davey, Do you hear a buzz when you touch pin 3 of the Lm386?? Here are a couple of things I'd look at: Check around the mute FET. Is there audio on the LM386 side? Also, coupling caps can be suspect. I ran a merry chase with a PIC-based CW decoder I build many years ago that only "kinda worked." I found with my primitive method (maybe an earphone--I don't think I had a scope then) that I had audio from the rig on one side of the cap and nada on the the other. Brand new expensive brand-name cap. I was a new ham/electronics tech then and I took it to a more advanced tech at work Nah, he shook his head. It all tested fine on the bench. He replaced the bucket with one in his stash and...voila--problem solved.? So, don't rule out weird flakiness. At another job early in my career (while I was still in school), I got stuck repairing these in-circuit test machine cards. The machines were ancient A few years (like 3) younger than me. I'll be 50 in July) and some parts were unobtanium. However, poor manufacturing processes at the plant caused the product we were testing to have big, bad issues that blue these machine cards out at an alarming rate. I could fix most of them easy enough--generally one of 3 or 4 parts (or a part related to them)-- typically, 4066 ICs or output transistors. But I had one or two in my stack NO ONE could fix. I rebuilt the entire section of one with new parts and it was still broken. I found another had a broken internal trace, but it couldn't be repaired easily with a jumper (I don't remember why now--physical constraint or something).? So, for those of you who are X-Files fans (I've be rewatching the series from the start), you know these machines might have a mind of their own! I did have a similar trouble with a mute switch, though, on another kit. The FET was out to lunch. -HRS H. Russell Smith, N0QLT???
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On Thursday, May 11, 2023 at 01:52:44 PM CDT, David Knapp via groups.io <renewables@...> wrote:
Yeah David, lucky. Today we had a blizzard so we went to the local cafe for breakfast to plan our day tomorrow & this afternoon I am stuffing parts onto my board, LOL. Davey - KU9L
On Thursday, May 11, 2023 at 03:18:22 AM MDT, David Wilcox K8WPE via groups.io <djwilcox01@...> wrote:
Davey,? You lucky guy. The only camp ground I live and work at is our retirement home on a nice lake. ?I am 78 and my wife is 71 and our handy man petered out on us this year so we are doing ourselves all the lawn maintenance and putting the boats, etc., in for the grands that don¡¯t come very often. ?Hope to get out in the yard soon and do some portable work as all this raking and hauling is making us both ?achey and tired before our time¡.. ha! ?Very little noise at out QTH since the AM radio business is less profitable and the AM radio station across the lake sold their property and took down their 4 tower directional antenna on 1310 (3 x 1310 is 3930 kHz). ?1330 kHz is a great frequency for statewide nets that I participate in occasionally. I have often thought of offering my handyman services to a camp ground in the winter but it has never happened. ?My wife keeps me busy enough. ?Fifty years together. She got a new ring and I got a wad of money for Dayton¡. Fair trade in this household and I don¡¯t wear jewelry.? Dave K8WPE since 1960 David J. Wilcox¡¯s iPad On May 11, 2023, at 12:24 AM, David Knapp via groups.io <renewables@...> wrote:
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Re: LM-386 Live or Die?
Hey Russel, Yes, those caps can be a pain. In aerospace, they over-filter everything so 10% can be junk and the noise factor stays low, coupling doesn't fit that bill of course. I build my projects in stages and test them before moving on, an artifact of my breadboarding projects. When I get home tonight if I am not too tired will get out my transmitter so it can be above my QRN level to test things. Cheers, Davey - KU9L
On Friday, May 12, 2023 at 09:20:56 AM MDT, Russell Smith via groups.io <n0qlt@...> wrote:
Davey, Do you hear a buzz when you touch pin 3 of the Lm386?? Here are a couple of things I'd look at: Check around the mute FET. Is there audio on the LM386 side? Also, coupling caps can be suspect. I ran a merry chase with a PIC-based CW decoder I build many years ago that only "kinda worked." I found with my primitive method (maybe an earphone--I don't think I had a scope then) that I had audio from the rig on one side of the cap and nada on the the other. Brand new expensive brand-name cap. I was a new ham/electronics tech then and I took it to a more advanced tech at work Nah, he shook his head. It all tested fine on the bench. He replaced the bucket with one in his stash and...voila--problem solved.? So, don't rule out weird flakiness. At another job early in my career (while I was still in school), I got stuck repairing these in-circuit test machine cards. The machines were ancient A few years (like 3) younger than me. I'll be 50 in July) and some parts were unobtanium. However, poor manufacturing processes at the plant caused the product we were testing to have big, bad issues that blue these machine cards out at an alarming rate. I could fix most of them easy enough--generally one of 3 or 4 parts (or a part related to them)-- typically, 4066 ICs or output transistors. But I had one or two in my stack NO ONE could fix. I rebuilt the entire section of one with new parts and it was still broken. I found another had a broken internal trace, but it couldn't be repaired easily with a jumper (I don't remember why now--physical constraint or something).? So, for those of you who are X-Files fans (I've be rewatching the series from the start), you know these machines might have a mind of their own! I did have a similar trouble with a mute switch, though, on another kit. The FET was out to lunch. -HRS H. Russell Smith, N0QLT???
?????????????????????????????
On Thursday, May 11, 2023 at 01:52:44 PM CDT, David Knapp via groups.io <renewables@...> wrote:
Yeah David, lucky. Today we had a blizzard so we went to the local cafe for breakfast to plan our day tomorrow & this afternoon I am stuffing parts onto my board, LOL. Davey - KU9L
On Thursday, May 11, 2023 at 03:18:22 AM MDT, David Wilcox K8WPE via groups.io <djwilcox01@...> wrote:
Davey,? You lucky guy. The only camp ground I live and work at is our retirement home on a nice lake. ?I am 78 and my wife is 71 and our handy man petered out on us this year so we are doing ourselves all the lawn maintenance and putting the boats, etc., in for the grands that don¡¯t come very often. ?Hope to get out in the yard soon and do some portable work as all this raking and hauling is making us both ?achey and tired before our time¡.. ha! ?Very little noise at out QTH since the AM radio business is less profitable and the AM radio station across the lake sold their property and took down their 4 tower directional antenna on 1310 (3 x 1310 is 3930 kHz). ?1330 kHz is a great frequency for statewide nets that I participate in occasionally. I have often thought of offering my handyman services to a camp ground in the winter but it has never happened. ?My wife keeps me busy enough. ?Fifty years together. She got a new ring and I got a wad of money for Dayton¡. Fair trade in this household and I don¡¯t wear jewelry.? Dave K8WPE since 1960 David J. Wilcox¡¯s iPad On May 11, 2023, at 12:24 AM, David Knapp via groups.io <renewables@...> wrote:
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Re: Sudden Storm RX Ver.6
One question: Is the 33pf cap CzBM on the band module needed or not? The Schematic on Ver. 6 show it and it is on the parts list but wasn't included in the kit or on the Band Module expansion kit. I hunted around and found this document that says normally Cz is shorted, I assume with a jumper. In this document, the other three caps on the band module are the same as the Ver 6 schematic, however, on some bands the Inductor values are different that what the schematic shows for those bands. I didn't have a 33pf cap, but borrowed a 27pf from one of the band modules and the sound in the headphones seems better, but not sure which way is best as I do not have an oscilloscope here. I order an assortment of 450 small caps for my experimentations that should be here Monday. This weekend I will get out my Penntek TR-35 and send a few mw of dummy load power to compare signals. Today I have a 250-mile drive to deliver water tanks and I won't have cell service on most of it. I am deciding whether to install a GMRS repeater or to fabricate a more expensive Simplex Repeater for our camp hosts who live in the lack of cell coverage zones. If I do not have 25 projects going at once, it ain't me, LOL. Compare the two attached documents for info on Cz. It appears is may work either way, but just looking for clarity. Davey - KU9L
On Wednesday, May 10, 2023 at 06:58:59 PM MDT, David Knapp via groups.io <renewables@...> wrote:
Cheers, Davey - KU9L
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Re: LM-386 Live or Die?
Yeah David, lucky. Today we had a blizzard so we went to the local cafe for breakfast to plan our day tomorrow & this afternoon I am stuffing parts onto my board, LOL. Davey - KU9L
On Thursday, May 11, 2023 at 03:18:22 AM MDT, David Wilcox K8WPE via groups.io <djwilcox01@...> wrote:
Davey,? You lucky guy. The only camp ground I live and work at is our retirement home on a nice lake. ?I am 78 and my wife is 71 and our handy man petered out on us this year so we are doing ourselves all the lawn maintenance and putting the boats, etc., in for the grands that don¡¯t come very often. ?Hope to get out in the yard soon and do some portable work as all this raking and hauling is making us both ?achey and tired before our time¡.. ha! ?Very little noise at out QTH since the AM radio business is less profitable and the AM radio station across the lake sold their property and took down their 4 tower directional antenna on 1310 (3 x 1310 is 3930 kHz). ?1330 kHz is a great frequency for statewide nets that I participate in occasionally. I have often thought of offering my handyman services to a camp ground in the winter but it has never happened. ?My wife keeps me busy enough. ?Fifty years together. She got a new ring and I got a wad of money for Dayton¡. Fair trade in this household and I don¡¯t wear jewelry.? Dave K8WPE since 1960 David J. Wilcox¡¯s iPad On May 11, 2023, at 12:24 AM, David Knapp via groups.io <renewables@...> wrote:
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Re: LM-386 Live or Die?
Not exactly. Is your kit built and working? Do you have that version's documentation?? I think Version 4 is the current one and my bare printed wiring board was Version 3. There were features and components added to my PWB that weren't on the Version 2 schematic. When the Version 3 board was created, that was when the trace disconnects happened and they weren't meant for my kit, I got it by "mistake". If I had known the history I could have had the jumpers in place already, but that isn't usually how I stumble upon my troubleshooting, LOL. Anyway, It's all good, but it sure reminds me of my aerospace days in that I was given a large box of assembled boards to test and troubleshoot. You had to be on your feet as some of the parts I would specify to have changed were $10,000 each. New technicians tended to always change the part they understood the least. I always tried to find easy fixes like solder shorts under IC legs, open vias connecting ground planes, and parts the pick and place machine installed backward despite all of the expert software and operator training. When it came to SMD parts, you needed a microscope just to see that tiny pepper flake of a capacitor. Davey - KU9L
On Thursday, May 11, 2023 at 05:35:38 AM MDT, Curt via groups.io <rhulett1@...> wrote:
So am I to understand that the WWVR kit has a problem with ground plane not connected everywhere? I have a version 1 board here new in the bag.? I am not used to dealing with unconnected lands on a PCB.? Is this documented somewhere? Curt KB5JO |
David Deitrick
David Knapp