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Showing posts with label antennas. Show all posts
Showing posts with label antennas. Show all posts

Saturday, December 21, 2024

KE5HPY's Altoids Direct-Conversion Receiver for 40 Meters

Click on the image for a much clearer view.

It is a thing of beauty.  You can see all four stages in there.  There is the Bandpass Filter in the upper left.  Below that is the VFO.  In the center you can see the SBL-1 mixer. Off to the right is the audio amplifier.  FB Chuck! 

Chuck KE5HPY writes: 

Allow me to add an endorsement of the joy and practicality of the DC receiver. Whether XTO, VFO or DDS, ring diode mixer, or Polykov, the DC IF concept is a real winner.  They really deliver wonderful audio and clarity that is very satisfying for homebrew builder.


Thought you might enjoy these photos of a 40 m receiver and built 10 or so years ago.  The design is straight out of EMRFD.  At that time, the Altoid tin craze was in full swing and this is one of several projects I stuffed in a tin.  This compact receiver has traveled on lots of camping and kayak trips where it delivered good DX reception using only a 30 foot piece of wire for antenna running back to the tent. It’s fun to hear intercontinental QSOs when you’re in the middle of nowhere. With my 40 m dipole attached at home, I think this little rig can hear anything my Icom hears.  

It’s great that you’re promoting this practical technology. Keep up the good work.

Wednesday, November 13, 2024

SolderSmoke #254 (Audio and Video Versions): Australian Hex Beam Eaters, Fake Wires, Hybrid Rig, Antennas, Mythbuster II Transceiver, Mailbag

Hex Beam Eater

November 13, 2024

SolderSmoke Podcast #254 is available: 

Audio Version here:  http://soldersmoke.com/soldersmoke254.mp3

Video Version here:  https://www.youtube.com/watch?v=ZiZwWY1CQgI

Opening:  Disturbing news from Australia!  VK5RS reports that his Hex beam was EATEN by Cockatoos!  So stop whining about your HOA problems, OK?  It could be much worse! 

FAKE WIRES FROM CHINA!  Oh no!  Even the wires?  There is a good video from Mattias.  I have it on the SolderSmoke blog.  https://soldersmoke.blogspot.com/2024/11/clip-leads-made-with-fake-wire-buy-good.html  Important to note that Parts Candy doen't have this problem.  Buy your test clip leads from our sponsor, Parts Candy.  Link in the column on the right or go to partscandy (that's one word).com

Bill's appearance on the Ham Radio Workbench.  (Bill made some overly harsh comments about radio rejuvenation, and was trying to make amends.)  But now we throw down the gauntlet.  WE CHALLENGE the HRWB guys to build -- to homebrew - our TJ DC RX.  They will experience JOO, JVO and the elite status that comes with having built their own ham radio receiver.  And if they go on to build a 10 minute transmitter, they can use it for CW contacts.  Like on POTA (Thomas!) 

Anniversary approaching:  In August 2025 we will mark 20 years of the SolderSmoke podcast.  And we have already passed TEN YEARS OF JULIANISMO!  Pete joined the podcast on May 26, 2013.  Thanks Pete! 

Question for the group:   Which SSB transceivers did Doug DeMaw build?  

Pete's Bench:  Thermatron-Transistor Hybrid Goodness.  https://n6qw.blogspot.com/2024/10/blog-post_20.html

Dean's Bench:  The new Hex Beam (watch out for Cockatoos!)  Now that Dean and I both have Hex Beams, we plan on pointing them at Southern California in an effort to talk to an elusive RADIO GENIUS. Stay tuned! 

Dean's Hex Beam -- A Thing of Beauty

Also homebrew random wire with T match tuner for attic.  RF Burns!  

SHAMELESS COMMERCE:   Please link to our blog and podcast!   Please become a Patreon supporter (I have been posting special content there).  Be sure to make use of the great boards, parts and kits available at Mostly DIY RF.   Still use the Amazon link on the SolderSmoke blog page. 

Bill's Bench: The new Mythbuster II (20 meters only).  Built in about 3 weeks. On-the-air, while still on the bench!  Worked Euope and South Africa QRP.   https://www.youtube.com/watch?v=6o9QerQ7jzg

Getting another CCI amp for the Dominican Republic. 

MAILBAG: 

-- Paul VK3HN,  talks about the nice sound of the Mythbuster II's receiver, and a new QRP rig from Dave Benson K1SWL. 

-- Rick N3FJZ sent some very kind words in support of the SolderSmoke podcast. Thanks Rick. 

-- Chris KD4PBJ sent us a very nice message.  Thanks Chris. 

-- Kevin from Belgium sent a nice blog post in support of SolderSmoke. 

-- John WB4BTL spotted his old call (from 1974) in my Novice Log.  

-- Dave KD2E spotted his Novice call in  my Novice log WN2TBB. He also  saw a good friend WN2EHE. 

-- Mehmet who has the awesome and useful WEBSDR of NA5B helped me with a Facebook problem.  Thanks Mehmet! 

-- Mike WN2A asked about the Yaesu FT-101 9 MHz VFOs. 

-- Phil W1PJE (from MIT!) writes about old broadcast radio shows. And some really nice words of encouragement. 

-- Grayson KJ7UM sent kind words of encouragement, and great background on hybrid rigs. 

-- Peter VK3TPM writes about the decline of blogging, but notes that blogs are useful repositories. 

-- Todd K7TFC sent me some additional Mostly DIY RF boards.  Thanks Todd! 

-- Ed DD5LP/G8GLM  Kind words on SolderSmoke, nice info on the G-QRP 50th edition. 

-- Bill AH6FC  Encouraging words and good info on solar.  Mahalo Bill!  

-- Michael AG5VG Building LC VFOs for 7 MHz.  FB OM!

-- Bob K7ZB An EE who likes the treatment of mixers in the SolderSmoke book.  

Tuesday, October 15, 2024

Two Great (but Old) Videos about Waves




I've had both of these videos on the SolderSmoke blog already, but an e-mail from Farhan reminded me how good they both are. If you are averse to older material you might not want to watch -- but you would be missing out on some wisdom.  

 

Tuesday, July 23, 2024

Some Pictures of SolderSmoke Shack South


That's me at the operating position.   Window looks out to the terrace and to the ocean to the East, the  Mona channel.  The shack is on the top (seventh) floor. 


Here is the view from the terrace, looking South.  The big terrain feature is Cabo San Rafael. 


From the terrace looking North. 


Looking East into the morning sun 


From the terrace looking West. 


Antennas will go up there.  Perhaps solar panels too.  


A bog portion of the shack is a workbench with tools and test gear.  


Yesterday an old friend from Santo Domingo, Luis Ernesto HI8LEZ stopped by.  Thirty years ago we were pioneers in the use of amateur radio satellites from the Dominican Republic.  Luis Ernesto is in the book! 

Monday, July 15, 2024

15/10 SSB Rig On-The-Air from HI7


I'm going to move the antenna up onto the roof (out of sight). 

 

Monday, June 17, 2024

1,280 Antennas at 12 GHz -- How Starlink Works


One commenter questioned why we went with the more expensive Starlink system.  The simple answer is that it is just better, faster, and more reliable than the alternatives.  Many people here are clamoring for this sytem, and they are doing this for a reason.  On speed tests I am showing downloads of about 150 Mbps.  That is fast.  The truth is that my wife is more of an innovator than I am -- she was the one who decided on Starlink.  

When we were installing this system, I didn't even know what they meant by "Dishy."  I didn't know there were motors in the antenna.  And I certainly didn't know about the complicated software and hardware that allow the Dishy antenna to track the Starlink low earth orbit satellites without the use of the motors.   The above video explains it all very well.  

This is all a great demonstration of what can be done with digital technology, microchips, software and UHF. 

Saturday, May 11, 2024

Helge SM/LA6NCA Activates Colorburst Liberation Army in Sweden!


FB Helge.   This is really cool.  I didn't realize until I saw the schematic at the end that he was on 3579 kHz -- that is the old color-burst frequency, and now the frequency of the Color-burst Liberation Army. 

It was challenging to do this without sidetone.  But there appears to be a bit of room left in the matchbox -- could he squeeze in a few more components for a rudimentay sidetone?  Maybe just a piezo buzzer across the key? 
VIVA EL CBLA! 

Wednesday, May 1, 2024

KE5HPY Builds a QRP Transmitter

 

FB Chuck, very cool.  Please send us more reports on this rig.  
Chuck has been on the blog many times, with many projects: 
73  Bill 
-------------

Bill/Pete:

 

Thought you would appreciate a recent project inspired by the fabulous EMRFD.  This started as a test bed W7ZOI universal tx to evaluate my stock of RF BJTs and employ some FT-243s in the shack.  That was interesting by itself but the 16-32 dBm output (choice of device really matters!) did not reach the intended targets using my 40m dipole.  So, add a W7EL RF PA and a nifty, clean 7W emerges after damping output from Q2.  The final is pleasantly efficient and needs only a modest heatsink to survive key down for 60 seconds.  KFS then reported S7-9.  Success.  Time to box it up and go XTO, add a meter output at 30dB down and an RF driven LED indicator.  Left room to add an ATtiny85 CQ keyer but ran out of time.  Had to move house and knock down my 40-6m antennas.  That was the most painful part of moving.  So this rig sits while I find a new place to hang antennas.  Eventually, the TX will get a RX mate when it is possible to box up a 40m DC RX with Si5751 and OLED display. Am still trying to solve how to mount an OLED display cleanly in an aluminum box. First, I have to reconstruct my workbench.

 

Keep up your good work, and that is no April Fool’s joke. 

 

73,

 

Chuck KE5HPY


Friday, April 19, 2024

Deep Space Station 43 -- Canberra, Australia

 

https://spectrum.ieee.org/apollo-era-antenna-voyager-2

From the IEEE article: 

The dish’s manufacturer took great pains to ensure that its surface had no bumps or rough spots. The smoother the dish surface, the better it is at focusing incident waves onto the signal detector so there’s a higher signal-to-noise ratio.

DSS-43 boasts a pointing accuracy of 0.005 degrees (18 arc seconds)—which is important for ensuring that it is pointed directly at the receiver on a distant spacecraft. Voyager 2 broadcasts using a 23-watt radio. But by the time the signals traverse the multibillion-kilometer distance from the heliopause to Earth, their power has faded to a level 20 billion times weaker than what is needed to run a digital watch. Capturing every bit of the incident signals is crucial to gathering useful information from the transmissions.

The antenna has a transmitter capable of 400 kilowatts, with a beam width of 0.0038 degrees. Without the 1987 upgrade, signals sent from DSS-43 to a spacecraft venturing outside the solar system likely never would reach their target.


Tuesday, February 13, 2024

Ferdy HB9DSP's 5 band Moxon -- The Moxhorn!

 
Click on the image for a clearer view

Wow, I couldn't even build a 2 band Moxon, but Ferdy has built a 5 band version.  He told me that he had to tweak the elements a lot to get acceptable SWR's on all the bands.  20 and 17 are especially tough, because they are so close in frequency.  

More info on his great QRZ page: https://www.qrz.com/db/HB9DSP

Thanks Ferdy! 

Sunday, January 7, 2024

SOTA Antennas -- FREE Antenna Modelling Software

 

Ed DD5LP writes: 

Hi Bill,
 Given that the audience of SolderSmoke is more angled towards home brew and self construction, I wonder if you would mind informing your listeners of a very valuable antenna design website that despite the high level of quality work put in, is not getting very many visitors and may therefore be taken down.

Access to the site is free and the URL is sota-antennas.com.

Despite SOTA being part of the name this is of use for all portable operators and indeed home stations as well. It is a series of online tools that not only defines wire lengths for building but also gives EZ-NEC like diagrams of the expected radiation patterns.
My favourite little jewel is in the off-centre-fed dipole section where the positioning of the feed-point is varied automatically to show you the bands the antenna will resonate on. So as an Example a 40m OCFD with a feed-point at 33/66% will not resonate on 15m however one with the feed-point located somewhere near 18/82% will.

The website currently supports Linked-Dipoles, Off Centre Fed Dipoles, End Fed Half Waves, Delta Loops, Half Squares and Moxon antennas. It could be extended to support others but that is unlikely if the current site is not used more.

Thanks Bill!
73 Ed DD5LP

Tuesday, August 1, 2023

Voyager, Canopus, JPL, and 74xx Logic Chips from the early 1970s


"So somewhere out there in interstellar space beyond the boundary of the Solar System is a card frame full of 74 logic that’s been quietly keeping an eye on a star since the early 1970s, and the engineers from those far-off days at JPL are about to save the bacon of the current generation at NASA with their work. We hope that there are some old guys in Pasadena right now with a spring in their step."

https://hackaday.com/2023/07/31/just-how-is-voyager-2-going-to-sort-out-its-dish-then/


Saturday, May 13, 2023

Jam on Radar Antenna of Jupiter-bound Spacecraft FIXED! Antenna deployed!

Great news. This stuck antenna was getting me down.  Three cheers for the ESA folks who fixed it from afar.  

https://phys.org/news/2023-05-stuck-antenna-freed-jupiter-bound-spacecraft.html

Here is how they did it: 

https://www.esa.int/Science_Exploration/Space_Science/Juice/Juice_s_RIME_antenna_breaks_free


The RIME antenna looks a bit like one of my dipoles! But it can look 9 km into the ice. 

And what a great name:  Jupiter Icy Moon Explorer.  Juice. 

Godspeed JUICE!  

Friday, May 5, 2023

SolderSmoke Podcast #246: PeteGPT! DC RX, Si5351, Franklin osc, Cuban DSB, Hex beams, uBITX mods, DX, 10 meters, MAILBAG

 

SolderSmoke Podcast #246 is available: 

AUDIO PODCAST: http://soldersmoke.com/soldersmoke246.mp3

YouTube VIDEO: (247) SolderSmoke Podcast #246: uBITX, Hex Beam, DX, High School DC RX, 10 meter SSB Rig, MAILBAG - YouTube

The AI Deep Fake Threat!  PeteGPT!

Hearing Aid info:  I can hear the cymbals in my audiogram adjusted Airpods.

Update on the TJ DC RX project – Several receivers working! https://hackaday.io/project/190327-high-schoolers-build-a-radio-receiver

Sunil’s company provides Nano/Si5351 combos.  With the KD8CEC software. Very cool.  http://amateurradiokits.in They have a new SSB dual band transceiver – the Airpal.

Mark AJ6CU helping me. Sent me Nanos with KD8CEC software. His uBITX Settings Editor seems very cool. https://github.com/AJ6CU/uBITX-Settings-Editor/releases/tag/V2-beta-1  Thanks Mark.  

Franklin Oscillators. 

Cuban Islander and Jaguey info.  Send more!

Fixing up uBITX 2   How Bill blew up TWO Raduino Nanos. My results with the KB1GMX mods. (see below)

Hex Beam work:  Adding 10 and 15 meter elements.  But now I can hear AM breakthrough from WFAX 1220 AM  (5 kW during the day),  So I made a high pass filter.

Made first contacts on 15 and 10:  Argentina, Brazil, Dominican Republic.

First contacts with both India VU3TPW and China BA4TB.  SSB homebrew.

sBITX news. Taking orders!

Pete’s 10 Meter SSB Project

Mailbag:

--Wes W7ZOI provided great info and analysis on the Franklin oscillator. And lots of great tech info on other topics: http://w7zoi.net/oldtech/ponder.html Thanks Wes!
--Lex PH2LB. uBITX mods. TO-18 Heatsinks. New stickers (see above).
--Kostos SV3ORA and Hans G0UPL about the Franklin Oscillator.
--Listening to HRWB 178: Great stuff, many old friends: George KJ6VU moved to Oregon. Thomas K4SWL on the show.  Ben, an old friend of Pete’s,  mentions John Zaruba K2ZA – the guy who gave me the DX-100. Wonderful connections.
--Thanks to Todd VE7BPO for sending me another AADE LC meter. I need it for the SSSS.
--Nick MONTV planning a 15/10 meter dualband SSB rig. Me too! See video.
--Trevor Woods in W. Australia – The portrait in Artie Moore’s shack. Chuck WB9KZY – Willam Ramsay
--LA6NCA Helge three tube RX. Regen or DC? Mike Masterson WN2A and I discuss.
--Mike WU2D video on Retro QRP rigs – Steve G0FUW discusses Severn rig long in the works –started 1983 and nearly finished!
--Tim Hunkin of Secret Life fame did video with speaker made from potato ship bag. Discussed with Tony G4WIF and others. Also, Tim has an amazing video on cutting holes in metal. On the SolderSmoke blog.
--Bob Crane W8SX will be covering FDIM for SolderSmoke!
--Glen VE3DNL working on a more sophisticated DC RX.
--Craig KC2LFI from the beach on Grand Cayman. FB.
--Steve EI5DD reports We have changed our name - The May Issue of the HAM RADIO IRELAND Magazine, Ireland’s only independent magazine for the Radio Experimenter: https://docdro.id/SHH0VEy
--Mike EI0CL on 15 meters with Dean KK4DAS. FB
--Howard N3FEL of the Penn Wireless Association wants to do a group build of a DC RX.
--Martin LW9DTR in Buenos Aires looking for help with the code for an AD9850
--Todd K7TFC – always helping other homebrewers.
--Really thoughtful message from Kevin WN7Z

uBITX 2

My KB1GMX mods to uBITX 2

Thursday, March 30, 2023

An Antenna for the High-School Direct Conversion Receiver (and Next Steps in the Project)


We have reached the point where we have to decide on an antenna for the high-school direct conversion receiver.  It needs to be simple and easy.  It needs to be something that students can easily install from a bedroom window in an apartment or a town house.  

We thought about an End Fed Half Wave, but 66 feet of wire seemed to be too much, and the EFHW would require both coax and the construction of a transformer.  That seemed like too much. 

So here is what happens with just 33 feet of wire (1/4 wave on 40 meters), with another 33 feet as a counterpoise.  I found that the counterpoise worked just as well spread out on the bedroom floor as it did hanging out the window along the outside of the building.  As you can see in the video, the counterpoise is really necessary with this kind of antenna.  It makes a big difference. 

We know that the students could have dispensed with the counterpoise by connecting the copper clad boards to a cold water pipe, but that might be difficult for them.  So we went with the counterpoise. 

After the antenna demonstration I ramble on a bit about the high-school construction project, and where the students could go from here. 

Tuesday, December 13, 2022

Save the Antenna!


SolderSmoke fans have an interest in saving this antenna because it is the site of one of the most amazing RF troubleshooting stories of all time:  Wilson and Penzias were trying to track down some noise.  At one point they thought it might be the result of bird droppings.  Uh, no, it was really the result of the Big Bang!  Please sign the petition: 

 

Friday, December 9, 2022

R-390s, KWM-2s, Airplanes, and Magnetic Loops -- A Really Interesting Interview with Ted Robinson K1QAR


Eric Guth 4Z1UG has a really interesting interview with Ted Robinson K1QAR.  

I really enjoyed hearing Ted's inspiring story: 

https://www.youtube.com/watch?v=SUUzlKMMANg

https://www.qsotoday.com/podcasts/K1QAR

Listeners will like the discussion of the R-390 and the KWM-2.  And his talk about airplanes.  And the joy of repair.  



Here is Ted's QRZ.com page:  https://www.qrz.com/db/K1QAR

Thanks Eric!  Thanks Ted! 

Sunday, September 11, 2022

An Especially Good (Old) SolderSmoke Podcast


February 22, 2008    
-- We were in Rome.  
-- I read a 1931 QST ad sent to me by my fellow "Hambassador" David Cowhig, WA1LBP; David was in Okinawa when he sent it. 
-- I describe Wes Hayward's comments about Pat Hawker, G3VA. 
-- I talk about getting on the air with my HW-8 (after fixing it!), re-tubing my Drake 2-B, and putting up a 30AWG antenna in Rome. 
-- I describe meeting up with Roman hams (including amplifier manufacturer I0ZY!) and visiting the local radio club.
-- The Science Museum in Florence, Italy. 
-- DSB from Rome with my NE602 rig. 
-- Tony Fishpool and Graham Firth's Test Gear book. 
-- An important corollary to Murphy's Law. 
-- Listening to SolderSmoke from safari, under the Southern Cross in South Africa. 
-- Ron Sparks calls in from Dubai. 

You can put on a playlist of all the SolderSmoke podcasts here: 

Friday, August 19, 2022

VK3IO's Wonderful Antenna Tuning System

 

I have been ridiculed because my manual antenna tuner (that is screwed into the wall of our car port) requires me to step outside into the cold or heat to change bands. 

On August 18, 2022  -- with my Hex Beam, not with the tuner -- I worked Ron VK3IO on 20 SSB.  Check out Ron's antenna tuning system.  He used the same balanced tuner that I use, but he has them set up for FIVE bands.  FB.  The wire antenna was working very well -- with 100 watts to the wire Ron was booming into Northern Virginia. 

Ron's QRZ.com page: 


Watch out for those spiders Ron!  


Friday, August 5, 2022

SolderSmoke Podcast #239: Hex DX, VFO Temp Comp, DC RX, Polyakov!, DX-100, Wireless Set, Farhan's "Daylight Again" HDR rig, MAILBAG

N2CQR Hex Beam Aimed at Europe

SolderSmoke #239 is available for download: 

http://soldersmoke.com/soldersmoke239.mp3

TRAVELOGUE: 

James Webb Space Telescope.  Mars returning to opposition in early December.   

BILL'S BENCH

Hex Beam K4KIO - on roof – TV Rotor – 20-17-12  Lots of fun.  Working Japan regularly, Australia, South Africa on long path 17,000 miles.  52 countries SSB since July 11.

VFOs and Temp stabilization.  Dean KK4DAS found my ceramic resonator VFO for DC receiver drifty. He was right.  So I built a real LC Colpitts VFO.  Got me into temp stabilization.  A new hobby!  An obsession.  HT-37 and Ht-32 parts. Ovens?  WU2D’s second VFO video.  Understanding thermal drift and how to address it. Split stator caps.  Cut and try.  

Built a Polyakov DC Receiver. https://soldersmoke.blogspot.com/2010/03/polyakov-plus-dual-band-receiver-with.html  Lauser Plus.  Lauser = Imp or Young Rascal!  DK2RS.  He used a ceramic Resonator VXO at 3.58 MHz.   Mine works great on 40 with VFO running 3.5 -- 3.65 MHz. See schematic below. 

On 40 AM with DX-100 and MMMRX.  DX-100 died.  12BY7 VFO buffer went bad.  How common is failure in this tube type?  Nice QSO with Tim WA1HLR about the DX-100.

Got my Dominican license:  HI7/N2CQR!  SSSS on the way.   Thanks to Radio Club Dominicano and INDOTEL.

Getting more active in the Vienna Wireless Society.  

BOOK REVIEW:  

"The History of the Universe in 21 Stars” by Giles Sparrow.  Written during the pandemic.  Published by Welbeck, in London. https://www.amazon.com/History-Universe-21-Stars-imposters/dp/1787394654  Also:  From “Atoms to Amperes” by F.A. Wilson available for download.  See blog.

SHAMELESS COMMERCE DIVISION:   

Todd K7TFC getting ready to launch “Mostly DIY RF.”   I used his TIA boards in my 1712 rig.  He will have boards like this and much more.  Stay tuned.

I need more viewers on YouTube.  They want 4,000 hours IN A CALENDAR YEAR!  Please watch!

FARHAN’S NEW “DAYLIGHT AGAIN” RIG.  Analog.  VFO.   Comments, observations. We need to get him on the podcast.  Maybe two shows: SDR and HDR. 

PETE'S BENCH

Time very limited. But still sharing lots of tribal wisdom.

Wireless set with tubes!

Tool recommendation – Air compressor

 MAILBAG:

Farhan VU2ESE – Speaking of big antennas “Whenever I look at the huge construction cranes in Hyderabad, I always think how one could make 160m, 4 element yagi using it as a boom..

Todd K7TFC in Spain, spotting Log Periodics in Madrid.

Andreas DL1AJG:  Can Biologists fix Radios?

Janis AB2RA Wireless Girl.  Expert on Hammarlunds.  And was my first contact with the Tuna Tin 2. She too was HB!

Peter Parker VK3YE on Owen Duffy VK1OD

Lex PH2LB on homebrew radio

Would this really be homebrew?  Mail from H-A-D article on FM receiver

F4IET a DSB rig from France

Ciprian got his ticket YO6DXE    

Josh G3MOT sent us a good video about the Vanguard satellite and IGY.

Dave Wilcox K8WPE bought Chuck Penson’s Heathkit book.

Rogier -- So many great articles and links from PA1ZZ

Bill AH6FC  Aloha. Retiring.  Wants to build.  Mahalo!

Grayson KJ7UM  Working on an Si5351.  Gasp.

Mike KE0TPE viewing YouTube while monitoring 6 meters.   He will have a lot of time to watch!

Chris KD4PBJ spotted Don KM4UDX from VWS FB

Mark WB8YMV building a superhet.  Having trouble with 455 kc IF can filter.

Walter KA4KXX Great comment on the Daylight Again rig. 

Ramakrishnan Now VU2JXN was VU3RDD.  Found lost Kindle with SolderSmoke book on it. Building SDR rig from junk box.  Trouble with the LM386. 

Pete, Farhan and Tony:  Shelves of Shame

Daylight Again by Farhan

The Polyakov receiver I built yesterday (from SPRAT 110, 2002!)

Designer: Douglas Bowman | Dimodifikasi oleh Abdul Munir Original Posting Rounders 3 Column