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write your own review of the DCXXB Transceivers.
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DL2NEP
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Rating: 1/5
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Aug 4, 2011 13:28
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Poor transceiver. BC stations insteat of HAM
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Time owned: 0 to 3 months
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I ordered a DC20B to replace my RockMite20. But this transceiver is horrible. Description looks nice but I can only hear BC stations with this rig. My RockMite can do that better! It was not possible to do an QSO. If you want an easy transceiver than you should build a RockMite. If you want a "perfect" QRP rig then take a look at the WildernessRadio SST-XX. It have a receiver like a big station. With the SST-20 I worked Japan from Germany with an 3ele Beam. I will sell my DC20B asap.
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WB0FDJ
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Rating: 5/5
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Jul 28, 2011 11:17
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Simple and effective
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Time owned: more than 12 months
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Update: I built this kit when I was on a roll and built a bunch of other stuff that winter. Haven't used it in a year so today I haul it out and fire it up. Within ten minutes, from MN, I worked a ham in WA and another in ME who was also running ONE watt, portable. If your looking for a simple project, this is it. I wound up mounting mine in a plastic case that snaps together so field stripping the rig takes a couple of seconds, for troubleshooting. Worth the money!!! Earlier review follows:
My kit came promptly by mail. Got it open and started playing with the board, inventorying parts, etc. Anyone getting one of these MUST go to the website and look at the TWO files there. One is more about the mechanics, the other the point by point building guide. If you can solder and read, you can build this kit. Once built it fired up the first time without a hitch.
However...and this is very typical of any of the simpler QRP kits...the xtal was off about a mHz, as expected. I moved the crystal to a small piece of perf board, soldered the crystal, a ceramic trimmer (5-55pF) and an 8.2 microH choke together to make a simple and cheap VXO. Once the board was wired to the rig I set the freq to 14060 dead on. (I get about 7 kHz swing). While the rig was still sitting naked on the table I worked, from MN, a ham in AL who was running 4W. We had a nice 20 min QSO, not just signal reports. I get 1 Watt out, running off of a simple 2200 mAh battery, which is enough.
So....simple to put together, inexpensive and it works. Maybe a few rough edges but for you are paying for you get an effective QRP rig that allows you to pursue some fun.
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WB0FDJ
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Rating: 5/5
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Mar 24, 2010 11:03
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Simple and effective
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Time owned: 0 to 3 months
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My kit came promptly by mail. Got it open and started playing with the board, inventorying parts, etc. Anyone getting one of these MUST go to the website and look at the TWO files there. One is more about the mechanics, the other the point by point building guide. If you can solder and read, you can build this kit. Once built it fired up the first time without a hitch.
However...and this is very typical of any of the simpler QRP kits...the xtal was off about a mHz, as expected. I moved the crystal to a small piece of perf board, soldered the crystal, a ceramic trimmer (5-55pF) and an 8.2 microH choke together to make a simple and cheap VXO. Once the board was wired to the rig I set the freq to 14060 dead on. (I get about 7 kHz swing). While the rig was still sitting naked on the table I worked, from MN, a ham in AL who was running 4W. We had a nice 20 min QSO, not just signal reports. I get 1 Watt out, running off of a simple 2200 mAh battery, which is enough.
So....simple to put together, inexpensive and it works. Maybe a few rough edges but for you are paying for you get an effective QRP rig that allows you to pursue some fun.
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G3CWI
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Rating: 1/5
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May 28, 2009 09:15
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Don't
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Time owned: 0 to 3 months
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Mine was for 30m. BCI makes the radio unusable. Nice case. Transmitter works well. A pity.
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KD7RDZI2
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Rating: 5/5
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May 23, 2009 03:18
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now SDR!!!
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Time owned: 0 to 3 months
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This is my experience after 2 days and this is already my second review.
I had a problem of overloading. Connected to a broadband antenna, I could hear false signals of broadcasters very loud while all real signals were just under the QRM generated by the receiver. That was strange. On the webpage of the designer, Steve Weber, it is stated that "the most notable feature of this receiver is that is almost totally immune to SWBCI... The use of an analog switch mulitplexer as the mixer completely eliminates this problem... Not only overload problems are eliminated, but due to the analog switchs used, rectification problems seen in diode mixers are also eliminated, hence the much reduced suseptablilty to AM broadcast interferance". Sounded good, was it advertisement or real true?
I took for granted that this was true, thus, the problem of overloading could only come from the preamplifer Q5 J310 or the amplifier U1, 4556. I decided to remove the U1 4556. I connected one side of R11 with a 0.1microF to the headphone jack (left output) and the other side of R11 again with a 0.1microF to the headphone jack (now right output). Connected the headphone jack to the line in of the soundcard and used the freeware WINRAD.
Here are the results:
- overloading is totally disappeared. Steve Weber had indeed a great idea using a 74HC4053 as a mixer!!!
- the soundcard makes the work of the U1 4556, that is it amplifies, and in addition does shape the sensitivity too.
- WINRAD adds DIGITAL FILTERS, DIGITAL AGC, NOISE REDUCTION, a SPECTRUM ANALYZER, fantastic demodulation and son on and so forth. Just compare all these features with those of kenwoods, yeasus and icoms...
I used an old 1.7Ghz pentium to run WINRAD. Slower computer might have problems running WINRAD especially when other applications are open. Faster the PC, the better.
Another place to improve performance would be to use a different preampli. The J310 is fine but I would have preferred a mmic such as the MAV-11.
The next step will be connecting the FCC-2 to have a real VFO.
Here below, you find my previous review.
--------------------------------------------
This is my review after one day of experience.
The kit required almost one month to be shipped, all electrolitics were missing, as well as two resistors and two screws.
The kit took to be assembled and tested one day. As a previous reviewer pointed out, the kit did not come with hook up wire that is required to connect the case mounted parts to the circuit board.
The case the board and components are premium quality. In general it was very easy to assemble. I would rate the board and mechanical design with a 5.
The toroid transformers inductors were the most difficult to wind and mount to the board.
I have not tested yet the beacon mode on the meter model.
The trimmer capacitor used to tune the receiver produces a change in sensitivity. Yes sensitivity!!! The receiver, when connected to a broadband wire antenna produces a lot of crossmodulation or whatever. Simply the front end is easily saturated. I hear radio exterior de espana and all other broadcasts in the 30meters band!!! It is impossibile to make a single qso in this conditions. I had a look to the schematic. It has a low pass filter a jfet preampli and the mixer and the other amplifier stages. I don't know where such a mess come from. In less then a minute, I connected a homemade preampli without any front-end, a passive mixer and a dds oscillator, an audio transformer and used the soundcard to make a direct conversion receiver and make a comparison with the DC30B. With my homemade receiver I just hear the signals as I should. With the DC30B I have heard just ghosts and phantoms. If I didn't make any mistake with the toroids, the receiver maybe needs also a high pass filter or a truly well made band filter at the input of the receiver.
As for the transmitter, it seems to me well designed.
Concluding, very good board and very nice case. Good transmitter, the receiver should be improved.
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JL1KRA
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Rating: 5/5
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May 21, 2009 21:25
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Entry to the QRP fun
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Time owned: more than 12 months
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I made previous version DC40A.
This kit provides very simple direct conversion receiver and simple transmitter of fixed frequency. Still the kit comes with PIC based functions including keyer. It will be a primitive fun that he or she can communicate with others in distance with such simple circuit. But the sucsess is coming after several challenge and struggle by themself. Appearently this is not a transceiver who wish to use Yaesu-Icom-Kenwood convenience.
There is a simple transceiver called 'Pixie'. This one is popular among QRP builders. Since the Pixie was too primitive with less parts. Only a few can reach real QSO. The DCxxB series are filling the void with well written manual and additional power and measures to broadcasting QRM.
Thanks to Hendrics kit which provide us such fun kit to enjoy amateur radio homebrew.
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K7VBY
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Rating: 2/5
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May 6, 2009 09:59
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DC20B Needs Work
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Time owned: 0 to 3 months
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The kit took two weeks to arrive and was assembled over a two day period. The kit did not come with hook up wire that is required to connect the case mounted parts to the circuit board. The two toroid transformers were the most difficult to wind and mount to the board.
I gave it a 2 because of design problems
1. The beacon mode on the 20 meter model does not work. You can store a memory location but the playback will not key the transmitter as programmed.
2. The trimmer capacitor used to tune the receiver produces no perceptible change in sensitivity and only very strong signals can be heard.
3. The frequency of the crystal is higher than stamped on the case (14.061 instead of the expected 14.060). The possibility of working another QRP station with this transceiver is doubtful unless in the immediate area.
A good use for the transceiver would be code practice, where all the stations are located close together in a building or small neighborhood. Beyond that I see no expectation of working a distant station unless used with a separate receiver. I understand the 40 meter model might be a better choice.
I exchanged messages with the Hendricks company concerning the beacon problem, but the support person was out of town for more than a month. It seems no other person has a clue to solve the problem.
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