Thursday, December 31, 2009
For €199.- the package contains, the receiver (oh well...), some earphones and a 110/230V power supply with an adapter for American sockets. OK, and a very short manual.
When first attempting to engage... nothing... ???? Ahhh, by factory default, the keys are locked. That was a surprise, honestly.
There are a couple of features not really standard to such receivers. One is RDS which can be used to automatically program the internal clock. Interestingly enough, the clock can be set to two time zones and daylight saving time can be toggled by a single key. Speaking of "FM", the tuning range is 76 to 108MHz. There are two memory pages for FM, which can be programmed automatically (aka. ATS) by a single key.
The ATS also can be used for medium wave and long wave. The feature scans the respective band and stores the strongest stations to memory channels.
The MW channel spacing can be selected to 9kHz or 10kHz at a well accessible switch on the right side panel. This side panel also carries switches for "auto time set", "tone" (news/normal/music) and AM bandwidth next to a potentiometer for volume and a rotary tuning encoder.
The left side panel houses connection for DC, headphones, line-out, record trigger and external antenna. Also to be found, a potentiometer for RF gain (nice touch!).
Now to the more interesting things, short wave and first impressions as a grabber receiver.
Frequencies can be selected in a couple of ways, hacking it in by using the key pad, up and down tuning keys (5kHz steps) or the rotary encoder on the right side panel. The steps of the encoder can be toggled between 1kHz/40Hz in SSB mode and 5kHz/1Khz in AM mode, a third position disables the encoder. Since fine tuning in USB/LSB is 40Hz, there is no need for a clarifier, which therefore is not present.
When tuning, the receiver mutes whenever the frequency changes by 1kHz, even when using 40Hz steps. Within the kHz, the receiver does not mute. Seems some PLL locking.
One interesting feature is the memory system. Whenever a frequency is typed in which is stored in somewhere, the memory system changes to the memory page which the frequency is stored in. The mode is change to the stored mode.
During the first night, the receiver was very unstable and drifted a lot, the QRSS test was very difficult, doubts raised on the usability of the receiver for QRSS. The major drift was in one direction only and slowed down with time. That made me believe that this drift was due to fresh components which were not aged. The second attempt was going much better, the gadget was left one for the best part of the day. Before the test, I switched it off for a couple of hours, to see the effects of the warming up. Stability is much better now than it was during the first test.
BTW, for QRSS the RF-gain feature proved itself as very useful.
I hope that further use will further age the frequency determining components and thereby increase the frequency stability. If that will happen, the ATS 909 will make a really nice portable grabber setup.
Sunday, December 27, 2009
Sunday, December 20, 2009
Sunday, December 13, 2009
- start a grab a some 10secs before the slot, and end it some 10sec after the slot
- put the spectrum in a file named after the slot + sequence number
- register and stack all files of a single slot (as it is done in modern astrophotography)
Friday, December 11, 2009
Wednesday, December 9, 2009
Hence, occasionally a WSPR station makes it into the visual
(displayed) spectrum. When I did my E-probe test, under comparably
poor condx on 30m, RW6XC came up, low enough to nicely be seen
on the grabber spectrum. The interesting part, a visual spectrum
of a single station can be compared to the signal to noise ratio
determined by the WSPR software.
Have a look:
Station monitored: RW6XC
Power (indicated): 5W
Distance: LN23AS -> JO22DA = 3059km
The other part of the test was, to see if and how many
station are received by this minimal setup. Remember,
this is an E-probe feeding a homemade direct conversion
Stations received during 24h using the E-probe:
So, second experiment, yes, you can receive stuff with absolute minimal gear...
Tuesday, December 8, 2009
| 2009-12-08 03:36 || W3HH || 10.140158 || -24 || 0 || EL89vb || 1 || PA1GSJ || JO22da || 7276 || 42 |
| 2009-12-08 13:40 || W1XP || 10.140242 || -17 || 0 || FN42fo || 5 || PA1GSJ || JO22da || 5546 || 51 |
| 2009-12-08 14:24 || RW6XC || 10.140147 || -19 || -1 || LN23as || 5 || PA1GSJ || JO22da || 3059 || 302 |
| 2009-12-08 09:46 || I0/N2CQR || 10.140152 || -24 || 1 || JN61fv || 0.02 || PA1GSJ || JO22da || 1283 || 334 |
| 2009-12-08 08:54 || F6EZP || 10.140189 || -20 || 0 || IN93 || 2 || PA1GSJ || JO22da || 1029 || 21 |
| 2009-12-08 07:36 || OK2SAM || 10.140199 || -23 || 0 || JN99du || 1 || PA1GSJ || JO22da || 1008 || 289 |
| 2009-12-08 07:30 || OE3EV || 10.140193 || -6 || 0 || JN88 || 5 || PA1GSJ || JO22da || 981 || 298 |
| 2009-12-08 07:42 || IQ4DJ || 10.140228 || -5 || 1 || JN54mq || 1 || PA1GSJ || JO22da || 955 || 331 |
| 2009-12-08 09:44 || GM4KGK || 10.140281 || -6 || 0 || IO68ve || 5 || PA1GSJ || JO22da || 955 || 131 |
| 2009-12-08 10:10 || OE3WGW || 10.140178 || +9 || -1 || JN88cj || 5 || PA1GSJ || JO22da || 937 || 300 |
| 2009-12-08 09:40 || IK1ODO || 10.140264 || -19 || 0 || JN35sa || 20 || PA1GSJ || JO22da || 814 || 344 |
| 2009-12-08 10:34 || DL5MHD || 10.140212 || -9 || 0 || JN58xc || 5 || PA1GSJ || JO22da || 699 || 311 |
| 2009-12-08 10:34 || DG7RJ || 10.140240 || -23 || 0 || JN58th || 5 || PA1GSJ || JO22da || 665 || 311 |
| 2009-12-08 10:46 || HB9TMW || 10.140144 || -25 || 1 || JN36gq || 5 || PA1GSJ || JO22da || 615 || 345|
- 26600/196 = 135,71
- 26610/196 = 135,77
- 26620/196 = 135,82
- 26630/196 = 135,87
- 26650/196 = 135,97
- 26660/196 = 136,02
- 26670/196 = 136,07
- 26680/196 = 136,12
- 26780/196 = 136,63
- 27000/196 = 137,76
- 27005/196 = 137,78
Monday, December 7, 2009
The darker regions on the spectrum are due to a local (The Hague) sideband station pulling the AGC to the max. But still, there is some F1A (FSK-CW) coming through... The cheap'n easy setup still allows for detecting weak signals...
Saturday, December 5, 2009
Additionally, there are some approaches mixing different frequencies, I will not go into this in the present note.
The trick is to end the chain of dividers with a division by two, creating a 50% duty cycle.
I would like to point your interest to some frequencies for which ceramic resonators are available. Those could be nicely pulled, given the ratios, the stability of a ceramic resonators oscillator seems OK-ish to give some results still. Assume 1kHz drift @ 5.5MHz. This would resulting in a 25Hz drift @ 136kHz, not desirable, would allow for first tests however. It is clear that care should be taken to avoid drift all together.
For crystals, one could consider moderate super-VXOs.
At the end of this message, a band plan is attached. Some frequencies I listed are actually outside the band, consider this as a hint to SDR-receivers, in particular when the last division could be by 4.
There are two candidates for QRSS marked in red. However, both require a division by 13 :-(
Simple solution "ripple counters"
- 138550 = 4.433619 / 32 (=8x4=2x2x2x2x2)
- 138550 = 8.867238 / 64 (=8x2x4=2x2x2x2x2x2)
One decade counter + ripple counter or flipflops
- 136533 = 9.8304 / 72 (=9x2x2x2)
- 137500 = 22.000 / 160 (=10x8x2)
- 138240 = 22.1184 / 160 (=10x4x4=10x4x2x2)
- 136533 = 4.9152 / 36 (=9x2x2)
- 138888 = 5.000 / 36 (=9x4=9x2x2)
- 138888 = 10.000 / 72 (=9x2x2x2)
- 144444 = 5.200 / 36 (=9x4=9x2x2)
- 136533 = 6.5536 / 48 (=6x2x2x2)
- 136533 = 7.3728 / 54 (=9x3x2)
- 136533 = 14.7456 / 108 (=9x3x2x2)
- 136533 = 16.384 / 120 (=10x3x2x2)
- 136550 = 2.4579 / 18 (=9x2)
- 136533 = 24.576 / 180 (=10x9x2)
- 136533 = 3.2768 / 24 (=6x2x2)
- 136533 = 3.6864 / 27 (=9x3)
- 136533 = 4.096 / 30 (=5x3x2)
Two decade counters + ripple counter or flipflops
- 136364 = 3 / 22 (=11x2)
- 136364 = 6.000 / 44 (=11x2x2)
- 137675 = 3.579545 / 26 (=13x2)
- 137675 = 14.31818 / 104 (13x2x2x2)
- 137255 = 14.000 / 102 (=17x3x2)
- 136364 = 15.000 / 110 (=11x5x2)
- 136364 = 18.000 / 132 (=11x3x2x2)
- 137500 = 5.50 / 40 (=10x2x2)
- 138889 = 5.00 / 36 (=9x4x2)
- 138889 = 10.00 / 72 (=9x8x2)
- 136389 = 4.91 / 36 (9x2x2)
Now, what to select, taking into account the band plan:
- 135.7 - 136.0 kHz
- Station Tests and transatlantic reception window
- 136.0 - 137.4 kHz
- 137.4 - 137.6 kHz
- Non-Telegraphy digital modes
- 137.6 - 137.8 kHz
- Very slow telegraphy centred on 137.7 kHz
Wednesday, December 2, 2009
- radiator total length: 327cm
- matching stub length: 46cm
Tuesday, December 1, 2009
Bonk bonk bonk ...
Bonk bonk bonk!!!!
But now, it seems, I am onto something. Receiving the mystery station from JN44AE now, 2037z.
The DCTL finally usable for QRSS? I hope so, I intended to use this sort of aerial for future journeys, to put signal in the air, or maybe receive occasionally...
Monday, November 30, 2009
Remember, the idea is to use as much as possible from the kit to build a 40m QRSS transceiver.
First consideration, phase 1 completes the keying and rx/tx-switching. We need that, phase 1 should be built w/o any alterations.
Phase 2: this is the VFO & buffer, well, we don't want a VFO, we want an (TC)XO instead, hence, I propose to postpone any construction to a later stage. If you really want to do some soldering in that stage, that's seems reasonable to do: Q18, C33, C83, C84, R55-R59, L16. This is the last buffer stage with a low-pass. At the other C33 we will couple in the XO.
Phase 3: TX mixer. I believe, the transmit mixer should be postponed. Really. Let's first the the receiver operational and take care about the transmitter later.
Phase 4: RX front-end and filter. The front-end we really need, I suggest to build everything but the filter. Since the bandwidth we are interested in is just 100Hz, the idea is not to use all four crystals for the filter, but just a single one. Here, some experimentation from my side is still required.
Phase 5: BFO, RX mixer, audio. BFO and RX mixer we obviously need... What audio is concerned, the preamp-stage seem reasonable to build, up to C12. R6 could be replaced by a trimmer and the a.f. final skipped totally, finally we want to feed the signal to the computer.
My preliminary opinion on the AGC is not to include it. It could be turned into a manual gain control (using R6 feeding bias to Q7's base) or made switchable.
UPDATE: All those considerations brought me to a point where so few is left of the original kit, that it would be the best to start from scratch, w/o a kit, with a given bonus.
Sunday, November 29, 2009
Saturday, November 28, 2009
The tuner suits my two marine radios, aka SSB radio telephones, IC-M700D and IC-M700TY perfectly. Could well be that the tuner will join one of the radios on board Pandia for /mm operations on 14.313MHz or PSKMAIL frequencies.
Most likely, the AT-120 will match Pandia's backstay, other configurations are thinkable however....
Thursday, November 26, 2009
Here a second option that does not require a spectrum display, in this method you will be using your ears instead of your eyes. This is now it works, and also why...
- pick a broadcast station or timesignal with proven stable frequency
- switch to USB (you should now here a 2kHz tone, that would be the carrier)
- set the dial 2kHz above the nominal frequency (this bring you close to zero beat)
- adjust the clarifier for zero beat
This is why this works, the HF3 has got a very wide side-band filter, I guess that saves the maker some money. Hence, the filter's passband is broad enough to even pass the carrier and LSB contributions, allowing us to adjust the clarifier w/o any further tricks.
Tuesday, November 24, 2009
Here are simple ones, I have not seen before:
- 3.6 = 14.000 - 10.400 = 14.000 - 2 * 5.200
- 3.6 = 14.400 / 4 = (2 * 5.200 + 4) / 4
- 3.6 = 7.200 / 2 = (5.200 + 2)/2
Three band MEPT:
#1 of the above combinations has added value, since the 14.000 oscillator could be modulated, providing a 20m MEPT at the same time. At the same time, cf. an earlier post, 14.000 can be down converted to 7.0599MHz by means of a 15m QRP crystal.
- 80m: 3.5999 = 14.000 - (2 * 5.200)
- 40m: 7.0599 = 21.060 - 14.000
- 20m: 14.000
As for the QRP crystal, know your sources: Box73, ESS, QRP clubs, etc.
Monday, November 23, 2009
The 22pF I experimentally confirmed for the version w/o the additional stage are now shifting the filter response far more upwards than wanted. To be more flexible, I decided to replace the 22pF capacitor by a trimmer capacitor with a maximum capacitance of 18pF. The first results are promising. The filter response is now centered to 10140050Hz, which hopefully provides much better reception than I gained with the last design....
Wish me luck!
Remember, the task is to generate a frequency of 3.5999MHz, using cheap and available components.
And here it is:
- generate 6.400MHz
- generate 8.000MHz
- mix! => 14.400MHz & 1.600MHz
- filter ...
- divide by four (FlipFlops) => 14.400MHz/4=3.600MHz
- filter ...
FSK by pulling on one of the crystals.
In my design, I would probably pull one crystal for modulation and the other for the TX frequency.
Now, that was not that hard, or was it?
Sunday, November 22, 2009
Saturday, November 21, 2009
Let's have a look:
Friday, November 20, 2009
Thursday, November 19, 2009
There are plans for this second one. Since there is a lot of space inside its' housing, there is room for modification and experimentation. Many years ago, I heard about a kit that converts a FRG-7700 into a transceiver. Cool, I thought, and forgot about it again. And now, the idea is back, with something that connects in either of the two, the FRG-7700 or the HF3. Both are double conversion superhets, both use a lower intermediate frequency of 455kHz. Using the generated frequencies, one could imagine to convert a single side-band signal all the way back from 455kHz to whatever the receive frequency would be.
I figure, it would be the question of just some NE612 mixers and two crystal filters, one for 455kHz (side-band) and one for the first intermediate frequency.
One further could consider to add some temperature control to the reference oscillator.
And, who knows, maybe this could be an easy way of producing some QRSS-signals too.
Monday, November 16, 2009
- Ll = 347cm
- Lz = 46cm
- Lc = none
- 3.500, 3.575, 3.579, 3.5999
- 7.000, 7.0599
- 14.000, 14.0989, 14.31818
- 21.000, 21.1489
- 28.000, 28.188, 28.322
Saturday, November 14, 2009
- 7059 => 21060 - 14000
Thursday, November 12, 2009
- U.S. 7.025-7.125
- The Netherlands 7.050-7.100
- Germany none
There are a couple of obvious candidates for which crystals are available:
- 7.100 => which can be generated by a 14.200 crystal (ESS) divided by two
- 7.059 => 11.0592 - 4.000
- 7.085 => 12.000 - 4.9152
- 7.096 => 3.000 + 4.096
There are a couple of other reasons why I would suggest a frequency between 7.093 and 7.097. First of all, it is very simple to build an oscillator for 14.200 with a single crystal, pull it down a bit and divide the signal using a FlipFlop. The second reason I would see in the possibility to create a very simple superhet-receiver (or transceiver) with the combination found under point 4. This combination could also be used as a simple MEPT, however, drift is more an issue in a design using the sum of two frequencies.
This leads to the obvious advantages of the two combinations using differences. Once again, a superhet is possible and in a difference of two frequencies, drift is less of an issue.
And here comes the mod to the kit:
- replacing all 11MHz crystals by 11.0592MHz xtals
- not building the VFO but an oscillator with a 4MHz xtal including a varactor for FSK
Wednesday, November 11, 2009
Tuesday, November 10, 2009
No comment... thus, Pandia is out of the water for winter, giving me the chance of doing some work on the hull and on other part otherwise difficult to reach.
All right, now, what's that to with radio? Well... what about installing some aerials in the rigging?
Hard cut here; the exercise motivated me to wire up the recently obtained Icom IC-M700TY for the first time. The radio is superb! Never before I had the privilege to experience a noise blanker that actually works, well, the radio has got one. The squelch (on SSB!) works well, it's just a switch, I will have a look at the schematics, my impression was, the squelch seems to be dynamic, flip the switch and after a certain while the receiver is silent. The AGC is very effective, it cannot be influenced. Therefore I think, the radio is (w/o mod) not really suited for QRSS. The radio is controlled by a "high precision" TCXO, whatever that means. Said TCXO however is about four times the size of a TCXO in an amateur transceiver.
Downside, one needs to know the frequencies one wants to operate on. We amateurs tend to flip over a range of frequencies and see what's on. Well, spinning a knob in order to scan the band is a no no with the IC-M700TY. Actually, scanning is, compared to more modern professional (marine) radios, not an option to this radio. Thus, know what you want and which qrg to want it on.
I assume, the IC-M700 is ideal for modes such as PSK31, Pactor, etc. and further for nets and similar channelized voice operations.
Friday, November 6, 2009
Wednesday, November 4, 2009
The design involves a 5.0688MHz canned oscillator, two pairs of anti-parallel diodes and some audio amplification (TL082).
Theoretically there also is a front end with a J310, but, it is not working, God knows why... need to look into this... Not oscillation, no attenuation, no amplification, no nothing....
I/Q works, however, the correct phase-shift adjustment is not easy, three parameters to play with. The sideband suppression (image canceling) is surprisingly good, with the proper phase-shift.
Presently the fun is spoiled by a major 50Hz contribution, I've seen that before, proper tins required ;-)
Saturday, October 31, 2009
Wednesday, October 28, 2009
- 6.5536 + 7.000 = 13.5536
- 6.5536 + 7.005 = 13.5586
- 6.5536 + 7.015 = 13.5686
Monday, October 19, 2009
The gear is perfect, really. It comprises the two maritime modes USB and F2B, but also A1A, A3E and LSB, which is unusual for maritime radios. This radio is intended for TOR (Teletype Over Radio).
As in all professional radios, there is no main dial (aka VFO-knob). The frequencies, RX and TX are independent, are selected numerically.
This is a no-nonsense professional radio, just like the one I was trained on for the General Operator's Certificate. The only difference here, no DSC. However, DSC could even be run externally, since the radio is prepared for TOR.
Sunday, October 18, 2009
Thursday, October 15, 2009
I'll be using inverters, such a 7404, maybe LS.
The oscillator will be a Pierce design.
The attempt will be to use as many gates of the inverter linearised.
As soon as there's more, I'll provide an update.
Wednesday, October 14, 2009
Frequencies the receiver should be receiving, standard crystal frequencies provided:
- 3995 kHz (BBC/DW) - 4.000 MHz
- 6130 kHz (BBC/DW) - 6.144 MHz
- 3965 kHz (RFI) - 3.9321 MHz
- 5995 kHz (Radio Australia) - 6.000 MHz
- 6015 kHz (TDPradio) - 6.000 MHz
- 9850 kHz (Radio Prague) - 9.8304 MHz
- 11995 kHz (RDP Int.) - 12.000 MHz
- 1008 kHz (Economic. Ch.) - 2.048 MHz
- 1548 kHz (DW) - 3.0721 MHz
Saturday, October 10, 2009
Thursday, October 8, 2009
The exam is written, new books did not arrive yet, no parties or other obligations... a perfect time to ... buy a new rig.
Which I did!
Now, there is an additional small big one sitting on my shelf. Small and big to the same time? Yep, I bought a Yaesu FT-450. Primarily w/o the internal tuner option. The very friendly dealer gave me the hint, that in fact buying the tuner-less FT-450 and the tuner ATU-450 itself later on will actually be saving money over buying the FT-450AT. We both agreed that this does not make any deeper sense, marketing-wise and could be explained by a stragetic error in Yaesu's HQ only.
Experience sofar, nice rig, however pretty useless without a manual! I guess, I will have to free space in the shack to allow easy access to the printed documentation. Some settings come along easy, for some settings one needs to dive deep into the menus. At a first glance, the rig seemed to be factory set to voice operators. Actually, I was even dissapointed with the CW capabilities at first. However, with the help of the manual, I am coming closer to settings which would satisfy my needs for comfortable A1A operations.
Things I liked directly:
- the key/paddle connects to the front face
- 3.5mm key- and phones-connectors
- nicely arranged display
- all dials positioned low
- flat "car type" fuses
- receives well below 100kHz (tested on DCF77)
- noise from the AF stage, even w/ volume set to minimum
- ATT on by default at lower frequencies
- single leads power-cord (not twin-lead!)
- tiny GND-connection screw
- a lot of the default settings
Settings settings settings...
Thus, more on the radio, as soon as I understood more of the transceiver's main, extended and hidden menues.
Saturday, September 26, 2009
Sunday, September 20, 2009
Sunday, September 13, 2009
Sunday, September 6, 2009
Saturday, September 5, 2009
Thursday, September 3, 2009
Tuesday, September 1, 2009
Using an appliance, one can set the rig to any random frequency, agreed, operating an MEPT homebrew-style, here are two options:
- 7.106 = 10.106 - 3.0
- 7.103 = 12.288 - 5.185
There is a somewhat more difficult approach however which would involve penning down crystals:
- 7.105 = 11.0592 - 3.9542 (1.)
- 7.105 = 11.000 - 3.895 (2.)
- 7.105 = 9.202 (3.) - 2.097152
- penned down 4MHz crystal
- penned down 3.9321MHz crystal
- penned down 9.216MHz crystal