I would have to say that the Sierra would be my first choice, primarily due to the fact that you can start with one band and then add additional ones as you progress. The rig is easy to construct, and comes with very detailed, understandable documentation. Tuning and alignment is simple, even without any test equipment. Cost of the completed rig, with all band modules, is comparable to that of a larger multi-band rig, and the Sierra has most of the 'most-wanted' features.
The Oak Hills are easier to build because there is simply more space on the board. Second, you populate the board, attach to the chassis, attach the pots and other parts to the chassis (the chassis is 1 piece) and then align, close the case and enjoy. The 100 needs an oscilloscope. Alignment cannot be done without it. Mine went back to Oak Hills for alignment. The 100a doesn't need an oscilloscope and is fairly simple to align. Just a voltmeter, and a receiver.
The Ten-Tec is tighter to build as there is less free space on the board, but for the beginner, there are test stages to ensure the last step was completed properly. (solder bridges, wrong resister/cap). It is harder to assemble because there are many parts to assemble to build the chassis and case. For beginners, Ten-Tec explains in good but simple detail how to align the radio PROPERLY. For instance, when aligning the receiver, they explain how to use a VOM to set the levels, while OHR just says to do it.
Both kits come with "just enough" wire. Don't make any mistakes, magnet wire is tough to find, but both companies will send you more if you make a mistake. Both have equally excellent tech support. The Ten-Tec kit taught me a few things about alignment that I used to re-align the OHR and get it to perform better. Both look great, perform very well (a very amateur point of view) and are a great deal of fun. Both do have some point to point wiring which can be messy to do, the Ten-Tec in particular has 2 short runs of coax which can be challenging. Both require the winding of some coils.
I took my OHR100a with me to London last January and sat down in a park across from the Marble Arch Underground station and along with a simple dipole, made many enjoyable contacts. I have an OHR100 for 40 meters, an OHR100a for 30 meters and a tentec1340 for 40meters. All are excellent choices but I prefer the OHR because of the better DC power plug set up, the Ten-Tec uses an RCA plug and it doesn't have reverse polarity protection (a simple mod).
In closing, my first choice is the OHR!00a, any band (the 100 is no longer made) and then the Ten-Tec, any band. Thanks for the opportunity to express my opinion and have a happy holiday
It's controls are simple and intuitively obvious. Performance is excellent. Cost is OK at around $150 - $250 at current prices. AND, being a Heath product, it is easy to repair or modify. That's definitely a plus for someone new to a technical hobby.
I have built two kits - comments on each below. I am not a very experienced constructor and I wanted to build something that worked and was useable plus looked reasonable at the end. Hence I built two complete kits - cases and finishing touches included. I found this approach very satisfying for the first "major" projects although now I am more inclined to breadboard any old lash up. I feel that complete kits build confidence and produce a finished item to be proud of.
LAKE DTR3 (80m, 1W)
Excellent instructions and guidance including first class telephone support from Alan Lake. DC receiver keeps it simple. 4 separate PCBs ease construction and testing. Took me about 3 weeks working 1-2 hours per night for say 3 nights a week. Great fun to build. Still use it regularly on 80m - my main QRP rig at home!!! Performance is excellent including very good receiver sensitivity. I don't like DC receivers due to the awkward netting technique and the double images but once you get used to it does work very well. I get consistently good reports on the tone.
OAK HILLS RESEARCH -SPIRIT (30m - 5W)
A more complex circuit and one larger PCB with closer component spacing. Not really a first timers project. However the instructions are very clear and the quality of the PCB is excellent (the component layout is very clear). The case and other hardware is first class and the end product is truly one to sit proudly in the shack. Performance is very good too. The built in key (an option I think) is very good. I like the receiver sensitivity and it is great being a superhet, although mine does drift annoyingly for the first 5 minutes of warm up. I just haven't got round to sorting it out! Construction would be in the order of 30 - 40 hours I think - done slowly and carefully in my case with only 1-2 hour sessions. The PCB is fairly dense and the components small so I would not recommend a long spell or work on it.
I still use it regularly - if fact I only have the DTR3 and this Spirit in my shack! 5W is a good level and gets good reports / results.
I would recommend either kit to constructors who want to make something they can use and want to have something which is "finished" not just a PCB and wires on the bench! The DTR3 is simpler and a great starting point for anyone who can follow instructions and solder reasonably carefully. Hope someone finds these comments useful.
I bought the "SST" a QRP kit from wilderness radio some weeks ago. I am not experienced in assembling electronic kits but I had no problems to put the pieces together.
Circuit diagram and layout are very stringent and the instruction manual is really excellent. The manual is very well structured, easy to understand and it covers exactly the information needed.
It took two evenings (about 2*3h) to get the SST done. It ran immediately, no bug fixing phase was needed. I have now operate it the first day.
I compared the SST to my home rig Icom IC701: Sensitivity and selectivity are comparable.
The SST seems to sound even a little bit clearer. The transmitter of the SST produces a very clear signal, nothing to complain about.
Gregor, DF2EZ C T-kit Model 1220 (and 1222) 2m transceiver kit
It has always been a desire of mine to make a VHF transceiver, something which I have noticed that there is a dearth of such projects for the amateur constructor.
Ten-Tec have a reputation of builders of fine HF radios, I should know I now have three! Since the introduction of the European Community "CE" Electrical Certification, Ten-Tec have withdrawn completely from the European market, however thanks to the efforts of the Radio Society of Great Britain, RSGB, exemptions have been made for the supply of kits. This exemption has allowed me to add another Ten-Tec to my "collection" and fulfil an ambition to make a VHF transceiver.
The T-KIT Model 1220 2 metre FM Transceiver is a PIC microprocessor controlled radio with 15 memories, built-in CTCSS and capable of power outputs of one and five Watts The addition of the model 1222 RF amplifier increases the power output to five and 35 Watts.
One of the things that I judge a kit by is the standard of the instructions and the PCB and this kit is certainly not failing in those directions. The book of words is substantial, running into a hundred or so pages, with sections for reference, assembly and service. The book of words has to be read thoroughly before hand, though I have to admit it was a tedious job at times, especially since I was eager to get started on the assembly. Another very tedious job that has to be done, is sorting through all the components and checking that they have been correctly supplied. I have to admit to skipping this stage, which in retrospect was not a clever thing to do. A vital header socket was missing and the wrong value of capacitor was supplied. Fortunately I was able to obtain these parts in the UK. Included with the manual was a large circuit diagram and board placement shadow drawing, an errata sheet and a handy reference guide printed on stiff paper. The other item of high quality was the PCB; the double sided circuit board with through plated holes was very well made, with a high degree of silk screen printing on the top side.
The assembly is sub-divided into eight phases, with a test phase at the end of each construction section. Testing was accomplished with the use of basic shack tools; trimmers, a short-wave receiver, a 2m VHF FM transceiver and a DMM. The use of a frequency counter was well recommended when setting up the receiver section, as I found it difficult to align the receiver by ear.
Each of the Assembly Phases has its own component placement and circuit drawings with double check-boxes against each section. I found it very helpful to read over each phase before starting as there are one or two tricky assembly stages. This is definitely not a "fifteen minute kit" each phase took between one and two hours, I estimate that there is at least eighteen hours assembly time, which for me was spread over a week or two, depending on my shift commitments.
Due to a mistake on my part, I managed to insert the wrong value of resistor into the supply for the display driver i/c, this and a faulty PLL synthesiser i/c meant a lot of fault- finding time. I have to sing the praises of T-KIT, they were very understanding with me as I had originally thought the PIC microprocessor was not waking up from a "sleep-mode", they supplied a replacement chip and a replacement PLL synth. free of charge, which considering the distance and the costs involved I appreciate very much.
It is refreshing to deal with Ten-Tec, which strikes me as a radio company which has not lost sight of their roots. Even the Warranty section was straight forward and almost down-right friendly. It is interesting to note one of the conditions of the warranty, which I have not seen before in any of the kits that I have built. Specific mention is made against the use of acid flux solder, using this solder invalidates the warranty.
Ten-Tec state that this kit is suitable for construction "build able" for the average amateur, though I would caution a novice or an inexperienced home-constructor to have the assistance of an "Elmer" at hand as the going can get rough at times.
The winding of coils is something that is a source of problems in many kits. the ferrite coils were all supplied pre-wound which was a good point and the coils that did need to be wound were formed over a screw thread with instructions as to exactly what was required from the winding, "looking at the coil from the top you should see five complete turns" rather than say wind five turns and leave it to the constructor to figure out what is really required. Another plus in my book.
I mentioned earlier that there is an optional RF Power Amplifier, the T-Kit Model 1222. I took-up this option deciding to get all the construction over and done with at the one time. This was fortunate, as it provided some work in the periods when I was awaiting the delivery of the integrated circuits. The 35W class C amplifier went together easily, the book of words was written in the same style as the model 1220 Transceiver. Testing is not really made until the amplifier is incorporated, finally into the main Transceiver. This RF amplifier can be utilised for other VHF radios, and could give a welcome boost to Handy Talkies, which is something I may do to my Yaesu FT23R at a later date.
Both these kits are complete, down to the last nut and bolt, so no scrounging and sourcing of components is required, which is something I revel in. A project is not really a true amateur radio project unless at least one component is scrounged from a fellow amateur!
The front panel controls are Spartan and functional; three rotary controls and four push-buttons. I have to say that I am worried about the rotary BCD tuning switch, it strikes me as being flimsy, having too much radial play and may not stand the test of time. The 15 memories are functional, with the provision for five memories with custom split frequencies.
The rear panel, has a SO-239 aerial socket, and sockets for an extension speaker and a data "packet" operation. The real panel is dominated by the heat-sink for the 35 Watt amplifier.
On air I have received reports that the mic-gain is set too low, after years of training myself to get the mic. away from my face I find it difficult to get the fist mic. close to my mouth and start shouting, SSB style! I am considering fitting a VOGAD amplifier to the kit to compensate for this, or altering the value of the mic. amplifier feed-back resistor. Something else and this is unique to the UK is the necessity to fit a 1750 Hz tone-burst generator. (The repeaters in the UK must have the 1750Hz tone to open-up the repeaters, CTCSS is a luxury. The repeater group that I belong to has eight repeaters and only one has CTCSS fitted, this will change as the development of a new generation of control logic progresses.)
I enjoyed building the kits, even when things were going wrong. At the end of the day I could have spent my money on a second-hand Japanese "black-box" and probably got a lot more "bells and whistles" for my money. This is a sad fact of home construction, when it is easier (and cheaper) to buy a "black-box" than it is to make ones own radio-gear, however nothing can replace the euphoria of seeing the kit suddenly burst into life before ones eyes.
Lake Electronics Carlton Three- Band Receiver
The Carlton is a three band direct conversion receiver with a pre-selector, product detector, audio pre-amp, low pass filter and audio power amplifier. The VFO utilises three switched frequencies; 80, 40 and 20m. The first thing that struck me was the amount of paperwork that came with this kit, some twenty-three pages, which puts the five or six pages from the Howes DX receivers into the shade. The instructions comprised of an Introductory letter, a Technical Introduction, Construction Notes on Component Identification and Soldering Techniques and a section on Fault Finding. Each of the three PCBs had three pages devoted to it with construction information, a circuit diagram and Component placement drawing and a parts list. Several pages were devoted to the assembly and cutting out / drilling of the chassis, which is vital as a pre-printed self-adhesive front panel facia is supplied with each kit. This for me was a welcome feature as I am not too good at markling up what pot does what or even calibrating the VFO dial properly!
The construction of the PCBs was straight forward, entailing the winding of four centre tapped coils. One "sticky-patch" concerned the identification of the AF Gain and RF Attenuation pots. It was not too clear which one was which, it would have been handy to have the values (10K & 4K7) written on the inter connection drawing, which is one of the Carltons main "working" drawings. An in- line power filter, an unusual feature not normally seen in kits is fitted to the +12V line as it enters the chassis.The receiver drew 50 mA from the supply. Mains Hum was very noticeable when I used my rotten wee constructors power supply, so I ended up using my RAYNET battery box, just as well, as it was needing a charge. The calibration of the 80m range was out towards the top end of the band, so more work will have to be made there. Received signals was not too bad, with my very limited aerial set-up, I managed to hear an Argentinian on 40m.
AM Breakthrough. The Carlton has a RF Attenuator control is fitted into the Aerial line which was of some use. VFO drift. No noticeable signs of any on the three bands. "Microphony," some was noted while tuning, which although was noticeable did not prove to be much of a problem. (Microphony is where the received signal appears to wobble when the receiver case is tapped or knocked.) It is usually combated with rigid construction techniques. For the "kit with all the bits", one item which was missing was a short length of strong, thick wire to connect the VFO PCB to the tuning capacitor which might have reduced this effect. Tuning, a Preselector pot is fitted, when the receiver saturates a soft pop can be heard, turning the control back a fraction and all is OK. There was an annoying characteristic when using the RF Attenuation pot. Every time the pot was turned there was an almighty crackle in the head-phones, which made listening difficult. The problem persisted until the wiper on the pot "bedded" itself in.
The kit with all the bits. Everything you need down to the last nut and bolt was included with the kit. It was a pleasure to build a kit like this. The only thing that had to be done was to drill-out the holes for the PCB mounting screws, pots etc. What a joy it was not to scrounge about in the junk box to get a nut to fit a particular screw. Everything needed was there.
The Carlton was a pleasure to build, construction was easier than some other kits that I have built. The short comings with this kit are few and it put the fun back into listening. This kit would appeal to the casual amateur band listener or it could (with help) be a good project to build for a newcomer to Short Wave Listening.
Thanks to all the above for their valuable notes