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Re: New to group and Query
bambazonke01
Hi Arv, and Group,
I've been looking at the CCA Version 3 by VU3WJM as it fits the 884 packset like a glove. I have to find someone who has that board available or else gear up to make my own. I've made some PCB's in the past. I think Far Circuits may make me one as well. You may have seen the 884 VHF packset being sold on e-bay for about $120 Canadian or $100 US. These sets are good for 6 meter FM but they are ideal to use for a rebuild in an HF packset. I have al kinds of HF gear and "Green Radios" but always enjoy a project like this BitX. As time goes on PCB problems will sort themselves out. In the meantime, I'll start collecting components. Jim VE3DDY --- In BITX20@..., Arv Evans <arvevans@e...> wrote: Jim VE3DDYthe PTO/VFO, a Huff & Puff stabilizer, and three additionaltransistors for T/R power switching. It is a bit tight, but it can be done. Sincethe RF stages require shielding from the lower power sections, the use ofvertical sections of blank PCB might allow parts of the circuit to be built on theseshielding partitions, thus allowing a more compact design.prefer that method of construction. Some of the PCB layouts are documented inthe FILES and PHOTO sections of the forum.modules (about 1 inch by 2 inches) that were then assembled to make up a verycompact layout.FILES and the PHOTO sections and review what is there. You will find severaladditional ideas for modification and upgrades.problems, there are many now on the BITX forum that may be able to help.like configurationto install a Bit-X perhaps for 40 Meters. Service.approx 170 X 110 mm (6.75 X 4.25 Inches)or smaller? |
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Re: New to group and Query
Arv Evans
Jim VE3DDY
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One of my BITX units is built on a 7 inch by 4 inch PCB, including the PTO/VFO, a Huff & Puff stabilizer, and three additional transistors for T/R power switching. It is a bit tight, but it can be done. Since the RF stages require shielding from the lower power sections, the use of vertical sections of blank PCB might allow parts of the circuit to be built on these shielding partitions, thus allowing a more compact design. PCBs have been designed and may still be available as well if you prefer that method of construction. Some of the PCB layouts are documented in the FILES and PHOTO sections of the forum. Some BITX builders have constructed the unit in several smaller modules (about 1 inch by 2 inches) that were then assembled to make up a very compact layout. By all means, read over the older email messages, then go to the FILES and the PHOTO sections and review what is there. You will find several additional ideas for modification and upgrades. Welcome aboard and good luck with your BITX. If you run into problems, there are many now on the BITX forum that may be able to help. Arv K7HKL _._ On Thursday 11 August 2005 05:37 am, bambazonke01 wrote:
Hi BIT-X'ers, |
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New to group and Query
bambazonke01
Hi BIT-X'ers,
My name is Jim and I'm new to the group. I'm a Canadian Radio Amateur and an avid experimenter. I have an old Chinese type 884 VHF radio packset into which I'd like to install a Bit-X perhaps for 40 Meters. Has anyone reconfigured the main Bit-X PCB to a smaller configuration approx 170 X 110 mm (6.75 X 4.25 Inches)or smaller? I also have similar size available for the VFO and PA modules. I've lots of reading to catch up on. Jim VE3DDY |
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Re: BITX in 2m band
ajparent1
Hello,
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I have also done transverter for 2M in the past as well as 2m RX designs. A good filter for 2m can be done with 3 coils of helix design using aperture (window) coupling. Constuction is a 3 cell box using 2 sided copper clad board material. I have also found it convenient to develope for VHF/UHF using modular construction. For BITx this would be the audio, modulator, carrier osilarot and IF stages on one board and encased then later stages in boxed. Connections between boxes is with coaxial cable for RF. The whole radio becomes a box of boxes. This appears difficult but allows good shielding and makes stage by stage testing easier. Good luck with 2M. FYI: I have tested early stages of the BITx for 6M without power amplifers. With only 1mW (.001w) the range was only a few miles but the signals sounded good at the other end and recieve performance is as expected. More work is to build the power amplifier chain and enclose it. Allison KB1GMX [FN42hh] --- In BITX20@..., "eb7hpm" <msraya@t...> wrote:
--- In BITX20@..., Paolo Cravero as2594 <pcravero@a...> |
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Re: BITX in 2m band
ajparent1
Hello,
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Harmonics resulting from mixer operation are not a problem if circuits are run linear with attention to correct signal levels. Attention to filtering is a requirement and at 2M leads must be short and use of shielding can be helpful. I have a old and still very good Icom IC245 (nearly 30 years old) 2M CW/SSB/FM that the IF is 10.7mhz for SSB and CW. However if the builder can use a 16 or 20mhz IF that is helpful. It is possible to build a good SSB filter at 20mhz. Allison KB1GMX --- In BITX20@..., Paolo Cravero as2594 <pcravero@a...> wrote:
Hi |
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Re: BITX in 2m band
--- In BITX20@..., Paolo Cravero as2594 <pcravero@a...>
wrote: Hifilter out unwanted harmonics +-n*10MHz at 144 MHz?different generation method.Good... good question. ;-) The Yaesu FT-290R have 4 passaband filters sintonized at 144MHz with the aid of varicaps as output of mixer (it has also a ring diodes mixer), it has a 11MHz FI, then I suposse this is not problem, having some narrow passaband filters (four etapes minimun). The consecuence of this is that the sintonization range will be narrow also, but this is not a problem. I want to use only at 144.300 +- 50KHz. ;-) I do not use varicaps for sintonizing.. I make a tranverter for 28MHz to 144MHz a year ago and it also have a 4 coil passaband filter little trickly to adjust. But no much problem afterthat. Howhever I not have made yet the tests. The 4 coil passaband filter must be enclosed in a box, and the coupling must be soft. A coil near the other coil assures soft coupling. It woks, as work for my transverter a year ago. Thank You for your coments. Greetings Manuel EA7ARX Just my thoughts, |
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Re: BITX in 2m band
Paolo Cravero as2594
Hi
Great to read about your BITX developments! I have one concern, though: will it be possibile to efficiently filter out unwanted harmonics +-n*10MHz at 144 MHz? I think VHF&up transceivers use higher modulation IF or a different generation method. Just my thoughts, Paolo IK1ZYW -- | QRPp-I #707 + www.paolocravero.tk + I QRP #476 | | SpamAssassin-based email antispam/antivirus solutions | \ Italian/English-to/from-Croatian translations / \ Skype: pcravero / |
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BITX in 2m band
Greetings to fellows BITX'ers.
The other day I was testing a VCO for the range of 144MHz with the interest of making work the BITX in 2m. The VCO oscillates from 125 to 145MHz approximately with a air coil. I use 2N2222 transistors, but I soon realized that the BFR90 worked quite better. It is mounted using the "manhathan style", with a copper panel like ground and "ugly" assembly. Then, the PLL oscillator works perfectly without no modification to this frequency, what doesn't stop surprising me. But, the stability is poor due to the precarious assembly, however it is working without problem. The following step was to inject the 134MHz signal (I use a FI of 10MHz original) to the amplifier of the original VFO made of two 2N2222, the amplifier works and the circuit was able to transmit and receive. However a output tank syntonized to 144MHz didn't exist in this test, the signal was very weak. Once installed a tank of 3 coils and an amplifier with a BFR90 I succeeded in extracting the 144MHz signal, not without an adjustment very critical and delicate. The BITX transmitted and received in 2m USB!! I could not have made more tests, neither place a front end syntonized to 144MHz :-( . If the time permits me I follow investigating, because the topic seems very promising. I ham working in a multiband/multimode design (80m/40m/20m/15m/10m/6m/2m) (AM/FM/SSB/CW). The idea is to carry out three PCBs: SSB GENERATOR; PA, LPF, BPF; Microcontroller, PLL and VCOs. The work possibly is never concluded for time problems, but at least it could remain like contribution to whom he or she cheer up to finish it. I put these schematics in the files section as soon I can. I like to ear coments to this developement. Greetings EA7ARX, ex EB7HPM/EC7ALV |
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Re: I am interested in EB7HPM PLL
Dear Manuel:
I want to be grateful to you for your courtesy in giving me the information for the construction of the VFO and second for the advices towards the group. In the weekend I will be constructing your project and I will be notifying you of my experiences. The VFO that it uses for the tests in the 40m band is a VACKAR that I extracted from a note of the magazine CQ Spanish edition of the year 1994, which is extremely stable and it gave me good satisfaction. The filter passband already calculates it for the 11m band. As for the use of this band in our country a rules exist at commercial level but it is not defined well at keen level and consequently many people buy for u$s 30 a transceiver and use it for personal ends. I belong to a tiny group that inside this band (contaminated by the high power) devotes himself to the experimentation and the activity DX with low power. From I am already very grateful to you by the help. Cordial greetings for you and the group. 73?s & DX from Argentina. CARLOS MOSCA |
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Re: I am interested in EB7HPM PLL
I'm Sorry Carlos, but the group's language is English. You may
prioritary to post in english. The mayority of others members only understand english. Good, You must compose the message in lowercase also, please. I can translate your question to english: "Dear Manuel: To conclude the construction of BITX I have a problem: to find a vfo circuit that was stable to high frecuency. Initially the xcver was adjusted in the 40m band only for testing purposes, but I don't have ham radio license yet and I could not operate it. I have interest to convert it to the 11meter band, in which i operate provisionally until I get the license. I encounter interesting your circuit, for that reason I ask for schematic of your VFO circuit used. I ned to cover 27.400 to 27.900. The VFO is working from 17.4 to 17.9 or 37.4 to 37.9. Another question is how to modify the program in order to cover this frecuencies that show in the display. I be apreciated for you. In principly I was thinking to build a DDS VFO, but the expense for single band operation was not justified. Perhaps when I have a license I face a multiband project with DDS. Thank You and Greetings from Argentina. 73's and DX. CARLOS EDUARDO MOSCA" I reply first shortly in English first, then in spanish. Carlos, el lenguaje del grupo es Ingl¨¦s, por favor postea solo en Ingles si te es posible, pues los dem¨¢s miembros del foro no te van a entender. Tambi¨¦n es normal postear en minusculas, hacerlo en mayusculas no est¨¢ bien visto. Respondo de forma breve a tus preguntas: -> The VFO is the same of BITX, I change de emiter-base and emiter- groud capacitor to 47pF value for 31MHz operation. I change the coil for a 1uH to resonate at 30MHz. This oscilator can work to 50MHz aprox. I put a AM varicap(high capacity) in series with 1nF capacitor to the oscilator coil. I put a 100K resistor from varicap to PLL output. I put a 39pF capacitor from emiter oscilator to PLL input. -> You can change the frecuency of BITX to 27 MHz, only changing the oscilator coil and the BPF filter coils and capacitors. But you must test if the 11meters operation with modified equipement in your country is legal. In my country this is not legal. -> The software don't have to be modified. It works from 0 to 180MHz unmodified, you only must to supply a apropiate VFO that got this frecuency. 73's and good luck. EA7ARX, ex EB7HPM/EC7ALV This in spanish: -> El VFO es el mismo que el del BITX, He cambiado el condensador que va del emisor a la base y del emisor a tierra por 47pF. He cambiado la bobina por un bote sintonizable de alrededor de 1 microhenrio para que resuene en 30MHz. Esta configuraci¨®n del oscilador puede funcionar sin problemas hasta unos 50MHz. Puse un varicap de AM(alta capacidad) en serie con un condensador de 1nF conectado a la bobina osciladora del VFO. Puse una resistencia de 100K desde el varicap a la salida del PLL. Puse un condensador de 39pF del emisor del transistor oscilador a la entrada del PLL, usando cable coaxial. -> Puedes cambiar la frecuencia del BITX a 27 MHz, tan solo cambiando la bobina del oscilador y las bobinas y condensadores del filtro pasobanda de la entrada. Pero debes asegurarte que puedes transmitir en 11 metros con equipos modificados en tu pais de forma legal, en mi pais no es legal. -> El software no es necesario modificarlo. Funciona desde 0 a 180 MHz sin problema, solo debes colocar un VFO apropiado que llege a esa frecuencia. 73's y buena suerte. EA7ARX, ex EB7HPM/EC7ALV |
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INTERESADO EN PLL DE EB7HPM
ESTIMADO MANUEL:
AL FINALIZAR CON EXITO LA CONSTRUCCION DEL BITX ME ENCONTRE CON LA DIFICULTAD DE HALLAR UN CIRCUITO VFO QUE SEA ESTABLE A ALTA FRECUENCIA. INICIALMENTE EL XCVER LO AJUSTE EN LA BANDA DE 40M A MODO DE PRUEBA, PERO EL INCONVENIENTE ES QUE AL NO POSEER LICENCIA NO PUEDO OPERARLO EN BANDAS DE AFICIONADOS. MI INTERES ES PASARLO A LA BANDA DE 11M; BANDA EN LA QUE OPERO MOMENTANEAMENTE HASTA QUE CONSIGA LA DISTINTIVA. ENCONTRE INTERESANTE TU CIRCUITO, POR ESO TE PEDIRIA SI POR FAVOR ME PUEDES PASAR UN COPIA DEL CIRCUITO VCO QUE UTILIZASTE. YO NECESITO CUBRIR DE 27.400Khz A 27.900Mhz O SEA QUE EL VCO LO HARIA TRABAJAR DE 17.4 A 17.9Mhz O 37.4Mhz A 37.9Mhz. OTRA CUESTION ES QUE PARTES DEL PROGRAMA TENGO QUE VARIAR PARA TENER ESTA COBERTURA Y A LA VEZ QUE ME LA MUESTRE EN EL DISPLAY. TE ESTARIA ETERNAMENTE AGRADECIDO POR EL FAVOR; EN UN PRINCIPIO IBA A CONTRUIR UN VFO DDS PERO NO SE JUSTIFICABA EL GASTO PARA UNA SOLA BANDA. QUIZAS PARA CUANDO TENGA LA LICENCIA ENCAREMOS UN PROYECTO MULTIBANDA CON DDS. DESDE YA MUCHAS GRACIAS Y SALUDOS CORDIALES DESDE ARGENTINA. 73?s & DX. CARLOS EDUARDO MOSCA P.D:MI DIRECCION DE EMAIL ES patch2052000@... |
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mini Ring Core Calculator
The easy way to calculate toroid cores. mini Ringkern-Rechner V. 1.0 was first published in German Amateur Radio Magazin "FUNKAMATEUR" 11/2000. The program is homemade and free for use by radio amateurs. Version 1.0a running on Windows 3.1 and up, but will not developed any longer. Version 1.1 is 32-bit, including English. With version 1.1.2 the program supports non-metric units. If the system language is English (USA) the units will preset to inch, foot and AWG. An additional tool allows the conversion of non-metric units. I hope that will make the life easier for US amateurs or for others when reading technical articles. |
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Re: BITX15 QSO got 1000Km
Hi Arv,
please see message 309 ;-) Recently low activity on 18 MHz, most of the time nothing to hear because of bad propagation (or bad antenna?):-( Most (far) stations I worked are from Bulgarien, roughly 2000 km? however, with the IRF amp running about 6 watt in a sloping dipole, feedpoint about 6 meters above ground. Best regards, Chris. I wonder what the distance per watt record might be for a BITXdesign? Is your 500 Km per watt the best accomplishment thus far? It mightbe interesting to hear from others regarding their DX accomplishmentswith BITX, and if there have been any BITX-to-BITX DX contacts yet? |
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Re: BITX15 QSO got 1000Km
Arv Evans
EA7ARX
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Congratulations on your license upgrade, and on the recent DX with the BITX15/20 transceiver. I wonder what the distance per watt record might be for a BITX design? Is your 500 Km per watt the best accomplishment thus far? It might be interesting to hear from others regarding their DX accomplishments with BITX, and if there have been any BITX-to-BITX DX contacts yet? Arv K7HKL _._ On Sunday 31 July 2005 10:28 am, vdberghak wrote:
--- In BITX20@..., "eb7hpm" <msraya@t...> wrote: |
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Re: BITX15 QSO got 1000Km
Concratulations with you extended licence and the experience of working
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on HF with the BITX. May be we will meet, Chris. PA3CRX --- In BITX20@..., "eb7hpm" <msraya@t...> wrote:
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Re: Modulator mod and dual conversion BITX
ajparent1
Hello,
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Turning the moddulator around should not negatively impact operation. My proto(20M) and testing the second (6m) show the revised is prefered for many reasons. The high noise suggests several things. You may have RF getting into the audio amplifier or one or more stages are oscillating when they should not. As to 6 meters, I've done enough building of transceivers for that band that dual conversion is viable with care. The reason I say with care is that more stages and more oscillators require good shielding more undesired signals are likely. Also more stages means more gain and that increses the possibility of unwanted oscillation. I am working on 6M and to date I have the entire audio, and IF section working and tested. I will use doubly balanced mixer (mixer with two transformers). Local oscillator will use PLL of my design. Another approach for those not wishing to build PLL is to take a crystal osc such as 35mhz and mix that with VFO of 5mhz to get 40mhz at good stability. In any case after 4 prior VHF radios the local osciallator system must be shielded and well filtered to keep undesired signals away from the rest of the reciever. Basic lineup for the 6m radio is 9.6mhz IF and filter (have those crystals). Q1 and Q13 transistors are 2n3866 (good VHF device) and the power amplifier chain willl not use IRF fet. I plan to use a VHF power transistors 2SC1970 and 2SC1971. Allison KB1GMX --- In BITX20@..., "eb7hpm" <msraya@t...> wrote:
Hello, BITXs!! |
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Re: BITX15 QSO got 1000Km
Ron Brink
Congratulations with those results in 15m band !!
73 de Ron
PA2RF
 eb7hpm wrote:
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BITX15 QSO got 1000Km
Yesterday Afternoon I make contact in 21.190 with the Canary Island
Station EC8AUZ, from the south of Spain Huelva, it make more than 1000Km!! Signal reply was 55. I am very happy. Mi BITX(15+20) with PLL outputs only 2W (I have IRF520 instead IRF510) in a dipole antenna in a building 30 m over ground. The propagation helped a lot. P.D: I am in error in my last post. The oscilator is 22MHz for a second FI of 10MHz. Greetings EA7ARX, ex EB7HPM/EC7ALV |
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