My father, uncle and my grandfather made their livelihood in large part by fixing things. My grandfather had a sign in his store:
We fix anything but a broken heart
My father was a watchmaker and when I was ready to go out into the world, he advised me not to become a watchmaker because in the future, watches would be electric and the movements in them would be replaced and not repaired. He was of course right.
My uncle repaired televisions, a dying business. I have a very nice but 10 year old Sony flat screen TV that failed. An internet search suggested one particular circuit board was the likely problem, but one on eBay would cost $250 and there’s a chance it wouldn’t work. New TVs of that size don’t cost all that much more, and newer ones have far more features — apps and things, plus a warranty. It’s not worth repairing (and not easy to dispose of either).
I have a cordless vacuum that died. I took it apart and determined that the problem lay in its circuit board. I’m sure I could get a new vacuum for less than replacing the circuit board.
Given my history and upbringing, it really galls me to throw stuff out rather than fixing it.
So, I’m going to try. I have a Ryobi P515 Reciprocating Saw and the blade has started falling out. Over time it fell out more frequently. I disassembled the saw and didn’t find anything immediately wrong, and concluded that it most be wear on the clamp that holds the blade. I tried new blades and that made no difference.
Ryobi P515 One+ Reciprocating Saw
This is far on the low end of reciprocating saws that usually run $100 and up (not including batteries). By the time I add batteries and a charger, a replacement might be $150 – $200. I already have a Ryobi One+ battery set, so I’m biased to try to keep with that ecosystem.
There’s no way anybody is going to repair my saw for $69, but I thought I had a chance to do it myself and I think I found the part that would have to be replaced, an ASSY SLIDING ROD AND BLADE CLA that costs $15.26 (plus $9 shipping).
Ryobi TTI-300309044 Assy Sliding Rod and Blade Cla
I was encouraged by the fact that Ryobi says this is a superseding part, so maybe the new part will last longer than the old one.
Update
I received the new sliding rod/blade clamp assembly, and was presented with a new problem, installing it. The process required removing two retaining rings:
Ryobi P515 Retaining Rings
I actually have a retaining ring tool, but it’s too large for these rather small and very stiff ones. I ended up grinding and filing down my tool until it fit and I actually got the rings off. Perhaps an hour later, the installation was complete and I was able to saw through a piece of rebar with the same blade that fell out after a few seconds before. SUCCESS.
Photo showing P515 opened, motor center, power switch and safety guard upper left
What still bothers me is that I put a blade in the old part and I couldn’t pull it out. Oh well.
I have two phrases I learned at Habitat for Humanity that give me comfort; one is:
Nobody will notice that except you
That didn’t quite work this time.
Here’s a photo of one of the Greater Charlottesville Habitat for Humanity job sites where I’ve been working the past few weeks. One of my jobs was to frame the access entrances to spaces under the stairs for 4 units. The job consists of cutting molding to size and installing it. The finished job looks like picture frames, so all the angles have to be close, and not all the entrances were perfectly square.
Habitat for Humanity houses.
I screwed up with the angle on one of the cuts and the end result was that I didn’t have enough material to finish the job. I felt bad about it. To try to correct the situation (with the approval a staff member), I took two scraps and carefully glued them together to make a piece long enough, sanded them down, and installed them. It was in a back corner of the utility room, behind a hot water heater, and I thought that with a little paint, no one would ever see the splice.
A building inspector, however, saw the entrance door and said: that space has no AC and as a result mold could grow in there; you can’t have a door. So this week when I arrived on site, all the doors and frames were gone and a drywall patch was in their place; my new job was to mud the patches, covering up any trace of what I did before.
Can you say “Big black rubber buttons” three times really fast?
The big picture
The Prunus J-429SW is an AM/FM/Shortwave radio with the ability to play MP3 files from a TF/Micro SD card or a USB flash drive. It can also act is a speaker when wired to another device with an AUX or earphone output. It’s powered by a BL-5C battery. The Prunus is available on Amazon for $19.99.
Prunus J-429SW (Amazon photo)
This model radio seems to be marketed to seniors, touting simplicity of operation and a highly readable display with large buttons.
Specifications
Brand
Prunus
Model
J-429SW
AM
522-1710 kHz (See Note 1)
FM
87-108 MHz (according to the box) The radio actually tunes 70-108.
SW
2.3 – 21.9 MHz
MP3 Playing
TF Card / USB flash
Input Power
DC 5V 500 – 1000mA
Battery
1200 mAh BL-5C (battery included)
Charging time
3-5h
Playing Time
5-6h (3-% Volume)
Speaker
50mm 4Ω 3W
Earphone
3.5mm
Dimensions
31 * 126 * 73mm
Weight
28g (radio) + 25g (battery)
Included
Radio, battery, user manual, USB charging cable
Prunus J-429SW Specifications
Generally, an AM frequency range starting with 522 kHz indicates a radio intended for the European/Asian market where the frequencies are in 9 kHz multiples. Radios for the North American market start at some multiple of 10, like 520. For radios with digital tuning this is a big deal unless the radio can be switched from one configuration to the other. This radio, however, tunes in 1 kHz steps, so it doesn’t matter. Testing confirmed that AM actually works, but it is the weakest of any radio I own.
I sold about 80 radios on eBay, but there were just a few that nobody wanted. I went through those to see if there was anything worth saving from storage. One radio looked like it might be worth further study, a Kaide KK-MP903.
Kaide KK-MP903 AM/FM/Shortwave radio / MP3 player
It’s a remarkably simple radio, with only 4 buttons, a volume wheel and a tuning wheel, but it is an 11 band radio, clock, alarm, calendar and MP3 player. The radio uses 2 AA batteries and has an earphone jack and a jack for an external 3V power supply. The antenna extends to 17.5″ and swivels allowing it to be vertical when the radio is on its kickstand, a fob on the end of the carrying strap.
It has AM (MW), FM, FM1 (70-88 MHz) and 8 shortwave bands from 5.95 – 21.85 MHz. The chart later on shows discrete ranges for the bands, but in practice, there are no gaps between bands; coverage is continuous. Tuning is digital. Repeatedly pressing the FM button switches between the FM and FM1 band. Repeatedly pressing the SW button sets the tuning to the start the next shortwave band.
Inserting a micro SD/TF card in the slot in the side converts it to an MP3 player. The same 3 radio operation buttons work as MP3 player controls, with function labels on the top of the radio.
This description was found on the internet, translated by Google from simplified Chinese:
The performance improvement brought by DSP technology to this radio section product: digital filtering, strong selectivity, no tandem; full-band frequency tracking and locking technology, no image and frequency drift phenomenon in short-wave reception; digital processing technology makes the sensitivity comprehensively improved, There are many receiving stations; built-in digital power amplifier, high power, low distortion; FM stereo output.
From https://www.gdjyw.com/myfile/count.asp?id=512
Also at the same site these specifications:
Frequency coverage FM: 87 -1 -108 +1 MHz MW : 520 -60 – 1710 +60 kHz SW1: 5.95 – 6.20MHz SW2: 7.10 – 7.30MHz SW3: 9.50 – 9.90MHz SW4: 11.65 – 12.05MHz SW5: 13.60 – 13.80MHz SW6: 15.10 – 15.60MHz SW7: 17.50 – 17.90MHz ( Shortwave frequency coverage is not narrower than the above requirements )
Signal-to-Noise Ratio FM: 98 MHz ≥ 50 dB AM : 1000 kHz ≥ 40 dB
Selective MW: 1000 kHz +/- 9 kHz ≥ 40 dB
FM stereo separation: ≥25 dB
Maximum current consumption: ≤ 180 mA
Maximum output power: ≥100 mW, maximum distortion ≤ 20 %
Size: 124*77*21mm
A brief test using just the whip antenna picked up many stations on shortwave. Here’s Radio Romania International on 7420 kHz on June 5 at 0010 UTC heard in central Virginia.
Kaide KK-MP903 AM/FM/Shortwave/MP3
The functions of the 4 buttons were easy to discover. There are basically 3 sets of functions, when the radio is off (clock, calendar, alarm functions with dates and time selected with the tuning wheel), when the radio is on (band selection), and when the radio is on and a micro SC/TF card is inserted (next track, play/pause, previous track). Counterclockwise rotation of the tuning knob increases frequency.
The small speaker does not produce rich sound on radio, nor is there any significant bass response even with good earphones. Sound is much better playing MP3 files.
The display is large and easy to read. In radio mode, the band is displayed along with the time and frequency. There is also a stereo indicator for FM. When the radio is first turned on, a button is pressed, or the tuning wheel turned, the display is illuminated with a pleasant amber glow. When the radio is off the radio displays the date and time. In MP3 mode, the radio displays the time of day, the track number and the elapsed time played in the current recording. It does not play files in the WMA format.
My only puzzle is how (if possible) to set the AM tuning step to 10 kHz instead of 9. I’ve found virtually nothing about this radio on the internet. I probably bought it on eBay a dozen years ago. One Chinese exporter still sells it for $25 (one presumes it’s legit).
Two radios with similar function, but significant differences
The Kaito KA29 received a lot of attention by reviewers when it became available in August of 2014, but I only got mine today. The Zhiwhis ZWS-603 is much newer, from December of 2021.
There are some striking similarities in the radios, inviting a comparison. At the most basic level, both units are AM/FM/Shortwave radios that add the capability to be used as external speakers, to play music files from TF/SD and record from radio or from the microphone. Both use the same BL-5C rechargeable battery format. Both have a graphic equalizer and fall into the “ultralight” radio category. The ZWS-603 goes for $25.77 on Amazon, compared to $34.99 for the KA29.
Here’s my nostalgia photo from December of 1967. My “radio shack” was a bedroom closet.
My “radio shack” from December, 1967
The Eico signal generator, the Lafayette KT-340 shortwave receiver and the Heath kit IO-21 scope were all built from kits. Sort of in the center is my first shortwave radio, a Nanaola 10NT-504, 10-transistor single conversion radio that covered LW from 145-375, MW, and shortwave from 1.8 to 28 MHz in three contiguous bands. It had Vernier tuning. Great little radio.
On the wall I can recognize QSL cards from Radio Moscow, RCI, CHU, WWHV, Radio Japan, K4USA and WNYW.
In the same file box where I found the photo, I found the instruction sheet for the 10NT-504, which I’ve scanned for posterity. Also in that box was my very first radio:
Gilbert series-tuned “crystal radio” schematic and build sheet
The ZHIWHIS XWS-603 appears to be the same radio as the HanRongDo K-603.
Zhiwhis ZWS-603 radio, Bluetooth speaker, MP3 player
What’s unusual about this radio
This one is not like anything I’ve used before in several ways. First, it combines a shortwave radio, an MP3 player, a sound recorder and a Bluetooth speaker.
I’ve come to expect digital displays to consist of 7-segment digits, or predefined messages or bars on the display, but the ZWS-603 is a general dot-matrix screen. This means that it can display menus and draw pictures. It can switch languages and display English, Chinese and Japanese. Also because of the dot matrix design, the radio can put up very large characters, including a very visible frequency display.
XWS-603 Screen Detail
While the display is visible, the button labels are tiny and very difficult to read except in strong light.
One feature that I have never before seen in a portable shortwave radio is a “Mute” button. Just as MP3 players have a Play/Pause button, this radio uses the same button provided for its MP3 function to mute the radio. It’s great for comparing radios.
The radio has relatively few buttons for its functionality, which means that many of the buttons serve dual functions. Multi-use buttons are not unusual, but these will take some getting used to. The volume control doubles as a “next station memory” button with a long-press to change the volume. The MP3 Next/Previous track doubles for up/down tuning in the radio, since it has no tuning knob (or knob of any kind).
In actual use, I didn’t find myself stumbling because of multiple use of a button (something that has been a problem with my Tecsun PL-330).
USB functionality
I plugged a USB cable into the radio and my Windows computer’s USB hub. Nothing happened except that the battery in the radio started charging; however, when I explicitly followed the instructions by plugging in the supplied USB cable directly into the computer, Windows installed a driver for the radio. Once that was done, two things happened. The radio became a speaker for the computer, and the TF card in the radio because accessible as a disk for the computer, where I could copy files. I’m happy to report that music files inside directories are accessible by the radio. When playing a music file, the file name is displayed. According to the advertising, it will also display lyrics for files with them. [Update: I had a defective USB cable.]
Note that the radio cannot be used when the USB cable is connected to a computer, although it can be used when connected to a dumb charger.
Bluetooth
The ZWS-603 is also a Bluetooth speaker. Switching between MP3, auxiliary audio cable (supplied) or Bluetooth input is accomplished with a Mode button.
I was readily able to connect the radio to my Samsung TV via Bluetooth, but I had to try twice before it showed up on my Windows computer. It also paired with an iPhone.
MP3
MP3 is rather straightforward. It has a the typical controls for Next track, Previous Track and Play/Pause. It displays the file names on the screen. When plugged into the computer, songs can be copied directly to the TF/Micro SD card in the radio.
The user can pick a particular song by number, entering the number on the numeric keys. It plays well with folders. Songs can be selected by:
Select all songs
Repeat the current song
Repeat songs in the selected folder
Play random songs
Radio
This device is sold as a radio, and it is that. As it comes, the full low FM range is available and the AM step is 10 kHz. The shortwave step is 5 kHz.
I’ll say right off the bat that AM performance sucks. At midnight I could not get a single clear AM station. I could hear stations but all were very noisy. FM was good as was shortwave, not on par with my Tecsun PL-660, but still competitive.
I tried daytime reception of WWV on 15 MHz around noon local time. It was a weak signal on my PL-330, but very weak on the on the ZWS-603 (with a shorter antenna), but it does demonstrate that the radio doesn’t mute very weak signals.
The MP3 track controls double as tune up/down buttons, and long presses scan for the next station. Repeatedly pressing the SW button selects the various shortwave bands. You can also enter the frequency directly on the number keys and short press Play/Pause. Stepping is quite slow, about 1 second per frequency change.
There are memory presets: 80 on FM, 60 on MW and 300 on shortwave. Stations can be stored manually by long-pressing the 5 key (sub-labeled MEMO), the number, and pressing Play/Pause. Long pressing Play/Pause starts a memory scan with automatic storage.
Recording
Recording can come from 4 sources:
Live sound recording
Aux input jack
Bluetooth
The radio
While the recordings are stored on the TF card, they are placed in different folders on the TF/Micro SD card. FMRECORD, for example, is the folder for radio recordings (not just FM) and microphone recordings go into the MRECORD folder. I thought the microphone recordings were quite good. Recordings can be made in 3 quality levels with 128-bit sampling the default.
Conclusion
The ZWS-603 is not going to take the world by storm. It doesn’t have sync/SSB reception. It’s not as sensitive as the Tecsun PL-330/PL-660 radios. There’s no tone/bandwidth control. It’s memory system lacks features. It doesn’t have a clock, and hence no alarm (it does have a sleep timer). However, the wide range of record/playback capability, Bluetooth, the imminently readable display, the compact size/light weight and a very nice speaker make this $25 radio a good deal. If the button labels were easier to read, it would be a keeper.
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