Data Recovery & File Conversions: Director/Projectors by Internet & Jaz

Earlier in July, I made a posting in regards to a data recovery and conversion project involving Syquest cartridges and Macromind/Macromedia Director and Projector files. As it turns out, that was the beginning of an even more involved project with Prof. Dan Boyarksi of the School of Design at Carnegie Mellon University which involved even more SyQuest cartridges, Jaz cartridges and files delivered over the internet. While the methodology behind the file conversions remained the same as that in the previous posting, the presence of internet-based delivery and Jaz catridges posed some new barriers which required some further research. The results are reported in this posting.

Internet Delivery

There are some cases where old files have been actively taken care of, and the medium format has been upgraded over time to ensure the files can still be accessed. This could be as simple as making sure that your files on floppy disks, ZIP disks, etc are copied over to a CD-R, or a hard drive and copies are made over time as the media and interfaces change. While this is great, as it ensures that the files aren’t “stranded” on a media which has become obsolete (e.g. SyQuest cartridges being a prime example), it doesn’t ensure that the files continue to be useful. In the case of the change to the CPU architecture and operating system of Macintoshes, classic executable files are no longer executable, and applications may refuse to import or recognize older files.

As there were quite a few files which had “made the jump” media wise, but were not immediately usable, it was decided that transacting the files over the internet would be the most convenient way of delivering the files for further examination and conversion.

Initially, the files were uploaded to a file-sharing service, and a link was delivered to me. After a quick examination, it was determined that this “direct upload” of the files was not a desirable method of transacting files over the internet as it resulted in metadata loss and loss of the resource fork. Only the data fork remained in the downloaded files. In classic Mac OS files, each file consists of a data fork and a resource fork. Loss of the associated resource fork often results in loss of file type/creator metadata, or even the entire contents of the file in the case of font files where all the data is contained within the resource fork.

To ensure that this data is not lost, it’s necessary to find a way to bundle the data together. Previously, the use of AppleSingle, MacBinary and BinHex were more popular in the days of early internet, email, newsgroups and BBSes for distribution of Apple files as they preserved the resource fork and data fork together in a single file. To use these formats requires encoding the file prior to transmission and decoding the file after transmission and involves the use of third party software. There is an easier way, namely, the use of archival software such as StuffIt! which creates .sit archive files with a compressed copy of everything. Unstuffing the file at the destination restores all of the data.

Unfortunately, these methods are not that straightforward, especially if you have to convince someone to install the software and walk them through as to how to use it. It’s especially complicated by the fact that I’m not a regular Mac OS X user, and I don’t own Apple hardware myself.

Luckily, the inbuilt Compress feature of Mac OS X generates .ZIP archives with the resource fork stored inside the “dot” files. By asking the sender to group all the files and compress them by right-clicking and using the Compress option, a ZIP file is generated with all the information and can be shared online and cross-platform with no risk of breakage. It requires no software installation as well.

After receiving the .ZIP file, I booted my Mac OS X VM and extracted the archive using Mac OS X, thus “reconstituting” the files with no loss of metadata.

The next challenge is to migrate this data from the Mac OS X VM to the Mac OS 7 – Mac OS 9 VMs which will perform the file conversions. Raw .dsk/.hfv can be renamed as .img/.dmg and mounted under Mac OS X, however, they can only mount as read-only as Mac OS X depreciated write support for Mac OS Standard (HFS) filesystem.

Unfortunately, there doesn’t seem to be a way to get around this issue, so instead, we will have to rely on an overlap in functionality, namely that Mac OS 9 supports HFS+ (Mac OS Extended), and thus we can create an image in Mac OS X in the Mac OS Extended format, and mount it under OS 9.

To do this, a disk image is created using Disk Utility with OS X Extended as the file system. Note the use of No partition map and no encryption. Enabling these features can make your image unmountable in the emulator.


Once the image is created, you can write files to it, then unmount it and copy it to the system with the emulator and add it as a virtual disk. You can rename it to .dsk/.hfv if necessary.


A few special system files show up, however, the files are preserved and mounted just fine in Mac OS 9.0.4 with no loss of fidelity. Just remember to make the image larger than you absolutely need to, to make sure the files fit. Further to this, you can also copy the files off from here into an HFS formatted .dsk/.hfv file generated by HFVExplorer and thus migrate the files back to OS 7.

However, I didn’t actually start-off with my process this way – instead I created a .cdr disk image with Mac OS Extended filesystem for burning to a CD in the hope that it would mount directly with no hassle by attaching the .cdr as a virtual drive to the VM. Unfortunately, this was not the case, because the .cdr image included a partition map in the beginning of the image. This appeared to be a GPT/EFI partition map, which OS 9 cannot understand. The image can be rendered usable by truncating the sectors containing the partition map off of the front of the image. In my case, the partition map resided in 0x0 to 0x4FFF bytes, so if you copy from 0x5000 to the end of the image file to a new file using a hex emulator, the resulting disk will mount successfully in the VM.

As a result, transacting files between modern Mac OS X “post-depreciation” of the Mac OS Standard filesystem write support is still achievable provided you have a Mac OS 9 VM to perform the intermediary copy from an HFS+ filesystem to an older HFS filesystem. This works provided the image generated from Mac OS X does not have a partition map. It may work with an older Apple Partition Map, although it was not tested. EFI/GPT are not understood by Mac OS 9, and thus do not work.

Iomega Jaz Cartridges

In addition to SyQuest cartridges, Prof. Boyarksi also decided to mail me two Iomega Jaz cartridges in the off chance that I might have a way to recover the data from them.


The Iomega Jaz was another external hard disk cartridge format, from the same creators of the very popular Zip disks. It wasn’t as popular as the Zip disks, but offered much more capacious and speedy storage. It was, however, quite expensive and offered 1Gb per cartridge (initially), before upgrading to 2Gb per cartridge. It had a tough time competing with the CD-R/CD-RW drives which became cheap and mainstream several years after introduction.


Not having ever prior dealt with Jaz cartridges, this post will be a good look at the cartridges themselves. These were 1Gb cartridges, one being originally PC formatted, and the other, originally Mac formatted. The price was US$98 according to the label on the front. It comes housed in a vac-form plastic clamshell which is similar to that of the SyQuest, but the disks are a more compact 3.5″-like form factor.

The clamshell paper inserts were different depending on their factory format.

jaz-outer-mac jaz-outer-pc

They also turned out to be “fold open”, and thus had some promotional material on the inside. They also had two spreads which could be used for notes.



The cartridges have a pentagonal shape, with a rounded top.


A label sits over the main body of the cartridge, but provision is also made for a spine label.


No write protect notches exist on the cartridge. The labels provided appear to be a plastic-type label, on clear plastic backing, which might be a design choice to avoid any paper fibres being developed near the drive mechanism as hard drives are sensitive to dust.


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The sides of the cartridge have guidance channels for aligning its insertion into the drive. The left side also has a cut-out notch to open the protective shutter which covers the opening.

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The protective shutter is a thin piece of metal which slides along a channel in the plastic case.


Internally, the disk is made of two platters, and thus, four surfaces each holding around 250MB. The density is about double that of a SyQuest EzFlyer 230MB which only had a single platter with two surfaces (if I recall correctly) storing 230MB. This design, of course, necessitates having four heads in the drive and is potentially vulnerable to disk slip/shift in case of shock which could affect the alignment of the two platters relative to each other.


The underside has the spindle interface mechanism, which has some vague similarities with the SyQuest in terms of the spindle centering “tangs” in the middle, but is otherwise quite distinct.


The cartridge is constructed with a number of small Phillips screws. Internally, the media is a very light golden brown colour, which is to be expected. There is a mechanism in the lid which has a springy hook to retain the shutter in the fully closed/opened positions. There is also some air-cleaning filters within the cartridge. I do not recommend opening the cartridge, as the shutter mechanism has a tendency to fall apart and require careful manipulation to realign.


Because it was in no way compatible with the SyQuest system, being a completely different system, I needed to source a Jaz drive to access the data. It was very fortunate that a colleague at the university I was studying at had a Jaz drive he was willing to loan to me to read-out the media.


The drive, from the top, boasts some visual similarities to the Zip drive, but is a teal green instead of the blue commonly associated with Zip. A window on the top allows for reading the top cartridge label while a cartridge is inserted, just as in the external Zip drives.


Cartridges are loaded through the front slot, with the front label visible during operation. An eject button is provided with an emergency eject hole underneath the loading slot. Two LED indicators are also provided, as per the Zip drives.

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There’s nothing particularly interesting about the sides …


The rear has two HD-50 connections for SCSI, with a termination switch that features three settings (on, auto, off). A SCSI ID selection push-switch is provided, along with a power switch and power input.


The underside features the model number V1000S, and some rubber feet.

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The power supply provided features both 12v and 5v outputs, although the connections were not determined. Because the unit was on loan, it wasn’t torn apart for examination …


Of course, just having the drive was not sufficient. The problem was how to connect the drive to the computer. As I only had a DB-25 connector on my SCSI card, and DB-25 to Centronics-50 cables, I couldn’t directly connect the drive to the computer. As SCSI cables get rare, it’s almost impossible to buy the cables you need, and even if you could, it would be cost-prohibitive.

Luckily, thanks to my colleague, he was also able to find an HD-50 to Centronics-50 cable, so I used one SyQuest external enclosure to “join” the Centronics-50 to Centronics-50 to make the bus complete to the DB-25 connection on the controller. He was sure he had an HD-50 to DB-25 cable, but he was not able to find it. But it does illustrate the challenges that one faces with SCSI – connectors and cables can be a challenge to obtain.

With the interface complete and functional, recovery was done using the same Linux recovery machine using ddrescue. The Jaz cartridges did both require some level of retries to recover all of the data, however, no data was ultimately lost. It seems that dust may have settled on the disk, or some areas had become magnetically “weak”, resulting in a number of retries to return the data. Quick experiments using sginfo showed that the drive does not return GLIST or PLIST data, which was unfortunate, as it seems there is no way to assess the health of the cartridges without (possibly) resorting to Iomega’s own tools.


Delivery of “classic” Mac OS files with resource and data forks by internet transmission is complicated by the fact that many existing file sharing utilities may not correctly retain the data in both forks when files are uploaded/downloaded from the service. This is not such a major issue, as Mac OS X based applications are moving away from the resource/data-fork model, and the loss of the resource fork and associated metadata isn’t critical to the functionality of the files which can still be identified by extension. However, with classic files, this can pose major issues and require extra work to overcome.

A method to encapsulate both forks for transmission as a single stream is to archive the files. Mac OS X’s inbuilt “Compress” feature creates ZIP files which retain the information, and has the advantage of not needing third party software such as StuffIt! does. This can be suitably “reversed” by unarchiving on a receiving Mac OS X based machine (or virtual machine in my case).

A complication is that the unarchived files cannot be directly deposited into an HFS filesystem (i.e. that used natively by “classic” Mac OSX and now termed Mac OS Standard filesystem) as OS X has removed write support for it. Thanks to the overlapping support for Mac OS Extended (HFS+) with Mac OS 9, it is possible to create image files under OSX that will mount under OS 9, and then can be copied over to an HFS volume if necessary for use under Mac OS 7.

Dealing with Jaz cartridges is conceptually identical to dealing with the SyQuest cartridges, with the difference being the hardware required to read the cartridge. Thanks to a colleague, I was able to loan the drive for a short period to recover the data, and proceed with recovery in much the same way as with the other media. I also had an opportunity to examine the structure of the cartridge itself, which marks the first time I’ve dealt with Jaz media and drives.

In all, it was another successful project, which resulted in further understanding of how to directly exchange data between Mac OS X and classic Mac OS in emulators without any loss of resource fork data or use of third-party applications such as StuffIt!

Posted in Computing, Tech Flashback | Tagged , , , , , | 7 Comments

Project: Sainsmart Forty-9er “3W” 7.023Mhz QRP CW Transceiver Kit

Even though I’m insanely busy, it seems I just can’t help myself when it comes to cheap Chinese kits available on eBay. Of course, having built most of the cheap radio-based kits already, there isn’t really that much to build anymore. But just as some people like to build model planes and trains, I find the whole electronics kit-building process to be a form of hobby that can be both relaxing and rewarding, and in the case of the Chinese ones, cheap and sometimes frustrating.

If you’re feeling a sense of deja vu, that might be because I did build two insanely cheap PIXIE QRP CW transceivers already. With those, you got half-a-watt for your (just under) AU$5, so about 0.1W/$. But what if I told you that there was an upgraded three watt version for AU$12.29, for a nice 0.24W/$? In the words of Jeremy Clarkson …. powwwwaaaaaaaahhhhhh!


Unlike the other kits built to date, this one is branded Sainsmart, and actually has a product page, although the English used on the page is rather amusing at times. The company seems to have a variety of kits and focuses on “open hardware”. Terms used in the description include an “American ring” (otherwise known as a toroidal core, local stuff isn’t “good enough”), “hearing frogs” (in reference to the audio from a competing kit known as “Frogs”), “suites” (which means kits) and “… the restaurant also has a client transmission” (which I have no idea what they mean).


Just like other kits, this one arrived in a bag, but this one was a rather large anti-static shielding bag with a resealable edge. Very nice.


Inside the package, components are grouped into individual resealable bags – from the left, we have a bag containing all capacitors; then resistors, inductors and ferrite cores; diodes, transistors, crystals and regulators; and finally plugs, sockets, enamelled wire, and integrated circuits. IC sockets are provided which makes for a “safer” construction experience, especially for beginners. While sockets and connectors are provided for power and antenna, no plug is provided for the key, so users should provide their own key switch and a 3.5mm plug.


The board itself is an attractive red colour, and is a double-sided tin-plated-through-hole board with solder mask and screen-printed top. Component values are not screen printed – it’s already quite cluttered as it is, so reference to the printed material is required. Because of the numerous components, the physical footprint of the board is noticeably bigger than the PIXIE. The good thing is that no SMD components are used in the design of the kit, making it easier for beginners to construct. The difficulties lie in the use of a hand-wound inductor (so a little work is necessary), and the use of mixed 4-band and 5-band resistors with vertical mounting. Overall, I would think this kit is suitable for beginner-intermediate level constructors.


The underside has a large ground plane with tinned strips at the edges for “connection” with a suitable metal shielded case, which is not included. The ground plane is well implemented with thermal-pads, which make soldering a lot easier and more consistent.


The unit is supplied with three pages of photocopied print – two pages are component listings and board layout with the final page being the schematic reproduced above. No information on circuit theory is provided, and although some Chinese is present, most of the text is also written in English which makes this a bit easier to construct.

At a brief look, the circuit comprises several segments. The NE602 is a double-balanced oscillator and mixer chip, which forms the heart of the device and derives its input power through a 78L08 8V regulator. It receives input from the antenna through C21, back-to-back surge protection clamping diodes D1 and D5, and crystal Y1 which I suspect forms the beat frequency in the mixer on pin 4 which drives the LM386 audio amplifier. The input to the audio amplifier appears to be switched during transmission, probably to attenuate the receive path which would have a very strong signal. A second crystal Y2 is used, which appears to be configured as an oscillator. The key controls a number of transistors which amplify the oscillation and send it to the antenna, where a number of inductors are used to keep the oscillation from leaking into the power and out-of-band oscillations from leaking into the antenna. This design is more costly and complicated compared to the PIXIE, with quite a few more transistors, inductors, an NE602 IC and twice as many crystal oscillators. Accordingly, I expect this to be a superior performer.

As with most modern kits, you’ll have to BYO solder, desoldering braid (in case you make a mistake), hobby knife (to scrape off the enamel) and side-cutters. In this case, you’ll also need a suitable 12V DC power supply.

Construction Experience

The whole construction process took two hours from start to finish while not rushing myself to complete it. One thing I noticed was the use of an ESD shielding bag on the outside, but all the components inside (even ESD sensitive ones) were packed in regular plastic bags. This wouldn’t have helped them against potential ESD damage, although that being said, most of the chips are fairly hardy.

I started construction by putting in the sockets, then capacitors, inductors, resistors, diodes, transistors, crystals and then finally the ICs. The clearances between components can get quite tight, so dexterous hands are essential. I found the board easy to solder, however, the wide holes also meant an embarrassing amount of solder flow-through occurred at many joints. The components also appeared to be of mixed batches, with the size of identical valued ceramic capacitors occasionally varying, and the print quality of the values being mixed. The resistors were mixed 4-band and 5-band resistors of 5% or 1% tolerance. The JST connector orientation silkscreened was incorrect for the pre-made wires. On the whole, there wasn’t anything show-stopping, and the components supplied were pretty much exactly as required.

As no construction guidance is provided, I will offer a few selected hints and tips:

  • L4 is the thinner core where 16 turns need to be wound, and L3 is the fatter core where 11 turns need to be wound. The enamelled copper wire provided is folded into a bundle, so take some time to carefully straighten it out without introducing any kinks. Cut the wire into exactly half to make winding a little more manageable. Wind with a little “tail” hanging out from the beginning and keep winding until the necessary amount of turns is reached, keeping the turns moderately tight on the core and spaced as evenly as possible. Cut the excess wire off, and leave the tail exposed. Use a sharp hobby knife and a flat surface to scrape away the enamel at each end, before tinning it with a thin coat of solder before inserting it into the board and soldering. It’s not hard, but it is a tedious process. In the case where vibration may occur, it may be sensible to apply glue to hold the inductors in place on the board and provide mechanical support.
  • Watch the orientation of capacitors and ICs – because of the compact design of the board, adjacent parts often have the opposite orientation.
  • Crystals have a “can grounding” point just next to them. Because of the proximity of other components and the distance from the pads to the crystal can, it’s not advisable just to flow solder, as it probably won’t make the connection. Instead, mount a short piece of component lead to the pad first, then bend it over the can and solder it at the top, then clip the lead. This may not be absolutely necessary (and too much heat can stress the crystals), but the grounding of the can may help prevent any stray emissions or intermodulation/interference. Since the pads were provided, I went ahead and did it anyway.
  • An extra 51 ohm 1W resistor is supplied as a dummy load. It’s useful for testing the circuit, but it’s not rated for continuous duty, so don’t run with the transmitter keyed with only the resistor attached as it may get so hot as to damage itself and set things on fire.
  • CP9 is marked as a polarized capacitor on the board, but has been substituted with a ceramic capacitor according to the print. Based on the components supplied, this appears to be intentional – but it does cause slight confusion during construction.


This is what the constructed board looks like – a very dense set-up indeed, and I’m rather surprised the main transistor didn’t come with a heatsink. This may be necessary if operating at high powers for a long time … depending on how much power is actually developed.


As usual, there’s some flux spatter on the bottom, but otherwise, everything’s rather neat and tidy.


Over half the enamelled copper wire remained, and I’ve soldered the resistor to one JST header lead for testing purposes. The other is just left flying for my bench supply.

Performance Testing

As I still don’t know my morse code, and I’m not allowed to operate homebrew transceivers on the air, I’ve just decided to run it into the dummy load for a few minutes to test it. The same momentary push-button key was used from my “hack” for the PIXIE, and the Rigol DS1102E was used to assess its output.

12v-operationThe board operated first time with no fixes or tuning necessary. With 12V supplied to the board, it consumed (approximately) 380mA (or 4.56W) when keyed, which is less than the 450mA the site claims. The output reached 9.96V RMS over a 51 ohm load, or about 1.945W of actual transmit power, which is only about 2W, or 1W less than the advertised value. This is slightly disappointing, but is still almost four times that developed by the PIXIE kit. The positive part is that there was no residual carrier leakage to the antenna when the transmitter was unkeyed, and the receive note and side-tone were nice and smooth.

The harmonic emissions seem quite present at 14.046Mhz, being about 24dB below the carrier at 7.023Mhz. This is only slightly better than the PIXIE, but considering the higher carrier power, the actual energy emitted at 14.046Mhz is higher, about 8mW or so compared to the 5mW of the PIXIE. However, higher level harmonics aren’t visible at all, seemingly effectively filtered by the toroidal inductor.

9v-operationWhile not officially stated, the circuit will also operate at lower voltages, with a lower output accordingly. At 9V, the output power is about 1W.


At 5V, the circuit still operated although the distorted asymmetric waveform is much more apparent. The ratio between the wanted fundamental and the harmonic emission has reduced as well. Output is only 75mW or thereabouts, meaning this circuit tolerates low-voltage worse than the PIXIE and is less suitable for 9V battery operation.

4-5v-operationIt can operate at 4.5V, but now the output power is 23mW. By 3V, the unit is unable to sustain oscillation at all and often tries to start up but quickly falls back to no output.

Using my more accurate U1241B (as opposed to the inbuilt panel meters on my Manson HCS-3102 power supply), when supplied with 12V, the quiescent current measured 11.75mA (less than the claimed 23mA) and keyed current was 373.3mA (also less than the claimed 450mA).

tonepurityListening to the output of the transmitter using my Winradio HF receiver, the output tone was mostly smooth with much less “rough notes” compared to the PIXIE. It’s a cleaner output which should make for more pleasant “crowded band” operation.


The Sainsmart Forty-9er is a beefed up variation on the classic QRP CW kit. While it is more than twice the price of the PIXIE, I think it’s well worth it even if it doesn’t meet the claimed 3W power output, as it has a much more consistent performing side-tone, a much nicer receive note, cleaner transmit signal and most importantly, close to four times the output power. It has superior filtering of higher-frequency harmonics, which should keep other radio users happy as well, although the output at the 14.046Mhz frequency is still somewhat high for my liking. It’s also a pleasure to build with a quality double-sided silkscreened solder-masked tin-plated PCB and had no missing parts. It does require a little bit of skill in winding the inductors, but that in itself is no great challenge.

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Project: CD2003GP+SC3610D FM Receiver w/LCD Alarm Clock (74-108Mhz)

My little “mission” to build random Chinese radio-kits from eBay continues with this rather odd and difficult kit. Unlike the other kits, this is the first to come with an LCD display, but is advertised strangely as FM Radio Kit Electronic DIY Hobbies Learning Suite Frequency range:72-108.6Mhz. The kit cost AU$13.59 including postage, so I thought I’d give it a whirl. It’s more challenging, but it’s also potentially more rewarding.



As far as kits go, this one is just like the rest, starting life off inside a plastic bag of sorts. This one has all of its components encased inside the plastic shell, with the shell taped together. On the shell, T2 is written in pencil on the rear.


Inside, the components were somewhat loose and rattling, and I feared the LCD may have broken in transit. Luckily, it proved to be intact. There are a few carbonized adhesive tape connectors for use with connecting the LCD – it seems about five or six are provided, which is good because they can be quite tricky to get on. The case is moulded, and while relatively plain, it’s still an attractive enclosure for a DIY kit. The PCB for the front panel and LCD is seen here, along with the speaker, bag of components, telescopic antenna, a brass threaded rod and the tuning knob.


The unit comes with a single double-sided A4 sheet of details, mostly in Chinese. A major section of one side is consumed by the trace pattern and silkscreen component guide, with the other part of this side of the page consumed by the schematic.


The unit is based around the CD2003GP, which is an integrated AM/FM radio IC. All of its AM capabilities are not used in this design, which is a bit of a shame. It also uses an SC3610D as an LCD display driver with AM/FM frequency display, clock and alarm functions. An TDA2822 is used as the audio amplifier, as is common with many of these Chinese kit designs. Rather interestingly, this kit utilizes two ceramic filter components which implies a 10.7Mhz IF is being used. This can be an attractive feature in case you want to use the IC as a downconverter of sorts, and should mean better FM selectivity than designs relying on passive-component filters. The output of the detector is on Pin 11 which should have the full FM baseband. No multiplex (stereo) decoding is offered, which is a little disappointing.

The display itself is basically a frequency counter which measures the frequency and displays when the radio is running. If the radio is not running (Vfm low), then it displays the clock and allows alarm setting. If the alarm is triggered, the 8550 transistor is turned on to turn the radio on (i.e. connect the batteries to the CD2003). It’s a pretty simple design, and the display is not strictly necessary for the operation of the radio at all.


The second (main) PCB is pictured above. It has a fibreglass style substrate with silkscreening on the top. Component values are directly silkscreened on, making it easy for construction.


Unlike the other board, however, it is not tinned on the underside and is merely lacquered. It does have a solder mask, although the regularity and sizing of the mask doesn’t always match the intended copper pad shape. It still feels like a good quality board to solder with, even though a few scuffs can be seen near one mounting hole. Interestingly. the antenna connection point seems to show a trace at the top of the board being used as a counterpoise (ground) for the antenna, which should improve reception performance.

Construction Experience

At the time I decided to construct the unit, I was a bit sick from the flu, so I was a little lacking in energy and filled with frustration. As a result, I didn’t end up taking many photos of the construction process, but I will comment on some of the things I discovered along the way.

The first is that the kit absolutely lacks any instruction as to how to put it together. The constructor must work out what to do from the silkscreening. It’s not that hard to do, but it can be more daunting for the absolute beginner.

Because the LCD was a pain-point, I decided to start with assembling the LCD board first. I decided to mount the LCD first, which was a big mistake as it made the chip-on-board module more difficult to solder. As a result, I did make a bit of a mess of the soldering and had to come back and redo it because of a solder bridge or two.

I would recommend starting by soldering the chip-on-board to the PCB. Unfortunately, the board didn’t solder as easily as I would have hoped – a fine iron and fine solder wire is recommended, but even then, the solder often refused to flow freely possibly due to oxidation of the board or bad “vias” on the sides. Regardless, if you can’t get each pin soldered down to the board (starting at the corners first), you won’t have the LCD display and alarm features! This is quite challenging, even for me, so I don’t think it’s a good project for an absolute beginner.

Following that, some ceramic capacitors and a crystal oscillator need to be mounted on the rear of the board. The umbilical cable can also be attached, noting your choice of colours for the different connections.

To assemble the LCD requires some directional light (to see the metallization on the glass), steady hands, some fingernails and the assembly of the “stamping tool”. The tool can be assembled by taking the brass head, putting the silicone insert in, and screwing the rod into the rear. Then, with a careful fingernail, separate one of the carbonized self-adhesive labels from its backing. Take care to align it with the metallization on the glass – you need to get it within about 0.3mm or so. Then press down on the back of the self-adhesive label where it is on the glass with the stamping tool to make sure the label is well-adhered.

Then, remove the backing on the self-adhesive foam labels on the PCB and align the LCD to the PCB. Lower it down onto the self-adhesive then push down on the carbonized tape and get that to adhere to the traces on the PCB, again using the stamping tool to ensure good solid contact. If you didn’t fold the tape, crinkle it or break it, then you’re probably okay as long as the alignment is right. If it’s not, you can peel it off and try with a fresh piece. It’s good that there’s a few pieces, so you can give it a few goes.

The front panel buttons uses “snap” type buttons. The snaps are included, and I tried to solder the edges into place, but they’re of a metal which solder doesn’t take to. Instead, you should probably tape them into place with adhesive tape as other manufacturers often do. The power button is not a soft button, and instead relies on a hardware power switch which threads through the hole in the PCB. As a result, the power button can be “cut” from the front panel button set.

The main PCB is populated as per the silkscreen, with the push button assembled with a cap and the tuning dial assembled with a small non-tapping screw. One thing to watch out for is the variable capacitor, which had very tarnished pins which would not take solder. Having some sandpaper to file off the legs seems to be a good idea. The resistors supplied are high quality five-band resistors, so if you’ve been used to reading the four-band codes, you’ll have a nice time rethinking your multipliers.

Wires to the speakers can be soldered, along with the wires to the board. A wire can be soldered to the tag for attachment to the antenna. I soldered the wires for the battery terminals, but you shouldn’t do this as one of the terminals needs to be soldered after it has been fitted to the casing.


The assembly looks a little like this – don’t be fooled by the inductor printing on the PCB either – the orientation depends on the winding of the inductor – one of them was not wound in the expected way. Another thing worth noting is that the capacitors in the speaker “circle” need to be bent flat against the board to assemble the kit correctly. Note that there are a few extra holes on the board where no components are fitted and no silkscreen print exists – no components are intended to be fitted into these places.


At this stage, it’s also good to consider bending the capacitors on the back of PCB2 flat as well, so that it will assemble more nicely.


To fit it into the case involves sliding the rear antenna in with the tag in-between the case and the antenna and using the larger threaded screw to sandwich it into place. You should have the antenna with the screw pointing outside in case you need to tension it in the future. The tuning knob has to be fitted with the small non-tapping screw. The battery terminals need to have the positive fitted into the bay and then soldered after insertion – note that the terminal order is opposite to what I would expect (namely the negative spring in the door). Don’t lose the door either – it’s not captive.

Hot glue is necessary to secure the speaker into place. Two screws are used with PCB2 (top two), four with PCB1 (corners only). The rear of the case shuts over, with a long tapping screw in the centre, two short tapping screws in the battery bay and two behind the antenna.

Tuning and Troubleshooting

At this stage, I do not advise securing or closing the kit until tuning and troubleshooting has been completed. Partial assembly is necessary to test the unit, however. Have the battery bay assembled so that power can be fed from the AA batteries and then apply power and observe the LCD.

If all is well, the LCD should show the time (if off) or frequency (if on). First turn it on and run the tuning dial through all the frequencies. Then turn it off and run it through all the hours and minutes (AM and PM) then alarm. Check that there are no missing segments or “shorted” segments – if you have a corrupted display, chances are, you have either some solder bridges on the LCD side of the COB or you might have a flaky carbonized tape connection. Check the connection by pressing down with the stamping tool – if the segments flicker, you might have an air bubble under your tape. If nothing changes, then it’s time to grab the desoldering wick. I needed a few attempts to get this right.

Once the LCD is working, tuning is easy as on the two right-most screws need to be adjusted on the rear of the potentiometer. The bottom one affects the tuning range – the LCD will read out the frequency presently tuned to and so tuning is a breeze – you merely need to adjust the screw until you can cover the whole FM band. The other screw controls selectivity, so you will need to find closely spaced stations and adjust for best audio from the tuned station.

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Rather interestingly, the tuning range does exceed the FM band – initially I had it set to cover this range, but later I decided to change it to 70 to 108.5Mhz, which partially covers the OIRT band. It’s relatively flexible although the tuning range does depend on the exact start-and-end frequencies. The indicated frequency is correct to within 0.1Mhz (it seems). Leaving a little slack at each end seems desirable as thermal drift can change the tuning capacitor range slightly.

If all succeeds, then you can continue to close the case entirely and screw it all together.


Don’t be alarmed if you have quite a few spare parts. It seems that this kit was packed by someone who knows better and provides about one spare component of each value (or more) so that in case you drop one and can’t find it, you’re not out of luck! That’s a nice touch!

In Use


The plastic casing is a bland white colour with a few scratches due to shipping. However, it is a rather nifty unit. The sound quality from it is passable – not great but not bad either. The mechanical power button is “inverse” – in is powered off, out is powered on. The alarm functions perfectly, and the unit keeps time well, allowing you to set an alarm time and the radio will come on. However, you must ensure the volume is set to an adequate level and the radio is “tuned in”, otherwise you’ll be waking up to static or silence. The choice of 74Mhz as the beginning range is a little odd – I tend to see 76Mhz as a more common value for Japanese and CCIR band radios.


The alignment of the casing isn’t perfect – it scrubs against the volume dial a bit and the headphone jack seems a little out of place.


The tuning wheel sits in place well, and with the number of screws involved, the unit feels relatively solid and sturdy. Unfortunately, the design doesn’t have any “feet” or lanyard, so it does feel a little jittery on a table, and could potentially dropped while carried. The case doesn’t resonate as badly as some of the lighter cases.


A little bit of scrubbing on the rear removes the pencil marks. The non-captive battery cover is less than ideal, but as a DIY kit, it’s not really easy to distinguish this from a commercial product when it’s properly built. I think it’s pretty good looking for a DIY effort.

As this radio is not a real digital tuning radio, it offers a halfway compromise in the form of a frequency counter on the front which shows what frequency you are tuned to. Because of drift in the components due to voltage or temperature, the tuned frequency can shift (e.g. if you’re tuned to 106.5Mhz, it could flicker and display 106.6Mhz from time to time). This doesn’t really affect reception so much as potentially cause annoyance if you insist that the display has to show the “right” number.

The LCD contrast was a little disappointing. It appears this type of LCD is best viewed from below – so if you sit it on a shelf above you, the clock is much more easily read. Unfortunately there doesn’t seem to be a contrast adjustment.

mpx-signalBecause it’s a mono receiver, it doesn’t decode the multiplexed signal and the audio output has the same on the left and right channel. However, in order to provide compatibility for mono and stereo headphones, it is wired using the outer pins only, so stereo headphones will have “phase reversed” audio on the two channels, which makes for an awful listening experience.

The filtering doesn’t seem to be too great on the output, so we can actually see the pilot tone and the stereo multiplex information on the output audio itself.

The audio recording at 96khz is here in case you’d like to examine it.



Even while I’m sick, I managed to conquer yet another cheap Chinese radio kit. This one differs from the other kits by providing a decent enclosure with an LCD screen that provides a frequency counter and an alarm feature. This makes it more functional and practical compared to the other kits. It also adds an additional dimension of difficulty to the kit, which is compounded by the lack of circuit theory and kit construction guidance. As a result, I don’t recommend the kit for absolute beginners, especially due to the tricky SMD COB soldering. Luckily, it seems a few solder bridges on the output drive pins to the LCD has no permanent adverse effects.

Its educational value is limited because of the lack of information, however, it does engage some logic skills in deducing how best to assemble the unit. It does redeem itself as well in providing extra components to compensate for potentially dropped/lost/damaged components during assembly, avoiding any last-minute scrambles to find a particular lost component. It’s also not particularly expensive, although, it doesn’t seem to be a highly popular or available kit. The lack of stereo decoding and AM functionality seemed a little disappointing though. Still, it was good soldering exercise, and kept me entertained for an evening.

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