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Re: Betr: 10Mc/s Crystal Filter
Ruud Jongeling
Hi Sam,
The link doesn't work although I checked it before. Now I uploaded the file in the filebox. 73 Ruud. --- In BITX20@..., pe2bs@t... wrote: Hi Sam,select the crystals for the IF filter and how to calculate the C's. You canfind the article on: .me I _____________________________________________________________________can't lay my hands on it.
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Re: 10Mc/s Crystal Filter
Hi Sam and friends, In the Farhan's home page, you can find a very good article about Ladder filters, I have been used with success...
Have a great day!!!! Celso - PY2XT GG66rf Some time ago there was reference to a method of selecting the best |
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Betr: 10Mc/s Crystal Filter
Hi Sam,
In his article "A Simple SSB Tranceiver" Farhan discribed how to select the crystals for the IF filter and how to calculate the C's. You can find the article on: . 73's Ruud -- Oorspronkelijk bericht -- _____________________________________________________________________ Je eigen persoonlijk e-mailadres bij Tiscali? Registreer nu een domeinnaam bij Tiscali. Ga naar |
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10Mc/s Crystal Filter
Sam Caldwell
Some time ago there was reference to a method of selecting the best
four crystals for the IF filter. Naturally, I tucked it away somewhere in my computer for safekeeping, and now for the life of me I can't lay my hands on it. Can anyone point me towards the original ( or similar ) material ? Regards, Sam C., ZL1SAM |
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Re: No 14 Mhz after mixer on Transmit
Hi David,
the fact that the receiver works well shows to me that the mixer works? If you have both signals on the mixer, the 14 MHz should come out. The only thing you can do is checking of the diodes polarity and the correct connections of the transformers but I think you did this already. My experience is that the mixed signal is so low in output compared to the 'unwanted' signals that I think your 14 MHz signal is present but you do not notice it. In the 'modifications' directory, I described an aditional (standard) coil that helped some. You can try that and try to have a peaked coil on 14 MHz to get the wanted signal. Keep us informed, Chris. When transmitting only the 4 Mhz (VFO) signal is on base of Q13 .mixer. any ideas? |
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No 14 Mhz after mixer on Transmit
David WardenDurkee
When transmitting only the 4 Mhz (VFO) signal is on base of Q13 .
The VFO level is about 1Vpp. The 10 Mhz modulated audio is about 600mVpp at the base of Q12. I can see my 10 Mhz signal at the mixer but no 14 Mhz exits the mixer. any ideas? The receiver works well. |
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Re: First PSK31 QSO with BITX17
The fact that there was no need to change the microphone circuit may
be means that also spoken word can be transmitted? With SSB, I made many QSO's. My antenne is a sloping dipole, I found out that the received noise and QRM is much less if I receive on the 10 mtr. dipole that is on the roof. It improves the S/N ratio (resulting in beter readebility) a lot. Chris. Just made my first PSK31 qso on 18.102 MHz with the homebrewedBITX17 I made an RTTY qso (rst 559 with Greece). No change of the mic |
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Re: BITX VXOs
Hello Rahul and friends
I built 6 different frequency (3, 3.58, 4.192, 7.151, 14.318 and 18.432MHz) VXOs all are very stable...I will update my homepage with a description of each one... when I start with these experiments I made a description you may see at; Sorry about the bad English, I learn it by my self... 73 From Brasil PY2OHH Miguel -- In BITX20@..., Rahul Srivastava <vu3wjm@y...> wrote: Dear Miguel,for 80mts range mentioned. But what I am more interested is the 18mhz tuning you mention, it makes making a 20mtr radio with 4mhz IF and 18mhz LO a snap. 400khz range gives more than adequate 20mtrs coverage. BITX, They use a classic Colpits oscilattor with 3 parallel xtals and a3010kHz For 20m I use a commercial 3 x 4194 kHz xtals covering 4190 to 3990kHz For 10m I use a commercial 3 x 18432 kHz xtals covering 18400 totoo), and the 10m version I built only the VXO.Service.
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Re: BITX VXOs
Hello Ron
I will post the pictures and make a description of the coil ... I use a fixed coil... one or two in series. The main problem is the coil... when you try to change with other who has the same indutance value it does not work... the coil must have only one layer, with a thin wire 0.15mm diameter or less... I use one or more adjustable ferrite cores ... I have also built a Huff-Puff 2 ICs VFOs who works fine ... it is a great deal ... look the pictures at the photos area in the HuffPuff Group. 73 from Brasil PY2OHH Miguel --- In BITX20@..., Ron Brink <pa2rf@y...> wrote: Ola Miguel,with only 3 xtals. Is the output stable over the whole range? Do you use one or more (switchable) coils in series with the xtals to cover the range? it) and now the VFO with Huff&Puff is also stable when I force it out- of-tune e.g. by placing the desk-lamp just above the vfo. Added one picture in the photobox. BITX, They use a classic Colpits oscilattor with 3 parallel xtals and a3010kHz For 20m I use a commercial 3 x 4194 kHz xtals covering 4190 to 3990kHz For 10m I use a commercial 3 x 18432 kHz xtals covering 18400 totoo), and the 10m version I built only the VXO.Service.
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First PSK31 QSO with BITX17
Ron
Dear BITX-radiofriends,
Just made my first PSK31 qso on 18.102 MHz with the homebrewed BITX17 with Arthur UX1HW in Ukraine. Only 5 Watts RF out from an IRF510 and an end fed half wavelength wire antenne from my attic window into the garden under a 30 degrees angle. I copied him 599 and he gave me 599 as well. Distance between our radiostations: 2100km. Conclusion; the bitx is a fine rig to make digimode qso's. Earlier I made an RTTY qso (rst 559 with Greece). No change of the mic input circuitry required. Only requirement; make your VFO stable, short time drift <10 Hz. I used the Huff&Puff circuit. A VXCO will also do fine. Bye bye & enjoy homebrewing Ron PA2RF ==========First part of psk31 qso=========== UX1HW UX1HW de PA2RF PA2RF PSE K e tt PA2RF de UX1HW GE dear my friend Thanks for your CALL ur RST 599 599 599 my NAME : Arthur Arthur Arthur my QTH : Kremenchuk Kremenchuk Loc : KN69QC HW? BTU PA2RF de UX1HW kkk |
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a source for Hard to find components
Mike W
Hi Folks,
I was browsing other newsgroups this morning, enjoying my new broadband connection when I came across a post referring to They have just about everything that I have been looking for in the way of hard to find components and cases etc. And I thought that I would share it with the constructing masses :-) in the hope that you find that much sought after part too. Many Thanks to Giancarlo Moda for the link. HTH, Mike W, G8NXD ps. I have no connection with the company -- |
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BITX Mods file
vu3wjm
Hi!
Have posted a file with few mods that I have incorporated. It is possible your version may not require them. I needed slightly higher IF gain mainly because of poor quality devices and low recovered audio. I still need to do a spectogram and confirm the passband. Some impedence matching maybe also required. Sorry for poor quality PDF, looking for better schematic software. 73 Rahul VU3WJM |
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New file uploaded to BITX20
Hello,
This email message is a notification to let you know that a file has been uploaded to the Files area of the BITX20 group. File : /BITX 20 V1,2&3 /BITXmod.pdf Uploaded by : vu3wjm <vu3wjm@...> Description : BITX mods and shunt IF amp arrangement You can access this file at the URL: To learn more about file sharing for your group, please visit: Regards, vu3wjm <vu3wjm@...> |
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Re: VU BITXers
Rahul Srivastava
Hi! Arv
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I did make a layout incorporating new changes. Unfortunately only legal software with me is EasyPC dos bought in 90s for all?it was worth then?, it still proves to be the work horse.
If I need the benefit of new versions I simply import its file do the necessary changes in demo version and save the print file. I will try to post the updated mods but the pdfs dont come out that good.?
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The IF mod ie the shunt feedback design is based on the IF stage of NORCAL NC 20 a completely discreet design. Rest all other mods have been already suggested on group by our friends world wide. Like the doubly balanced mixer audio changes etc. The linear even follows the the trifilar mod. Surely I have recommended all making the board to put a bead on? PA fet? gate leads. I was forced to incorporate the IF mod not because it lacks in performance in BITX design but unfortunately the stock devices , mainly chinese that we get here in abt far east are not up to the mark.
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Just now I get a call the ver3 apperas to be a much better performer than the earlier version, need to check it out tomorrow.
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73
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Rahul VU3WJM
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PS:
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Lately I found that ?this diptrace software is also good:
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I could have have edited the original schematics but I feel Farhan work must carry his credits. I will try posting??the mods incorporating the changes.
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Arv Evans wrote: Rahul __________________________________________________ |
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Re: VU BITXers
Arv Evans
Rahul
toggle quoted message
Show quoted text
Has anybody drawn up an updated schematic to show the changes from Farhan's original circuit? If available, this might help others upgrade their older BITX20 units, and could help new builders focus on the newer design. Thanks, Arv K7HKL _._ On Fri, 22 Apr 2005 22:08:57 -0700 (PDT), Rahul Srivastava <vu3wjm@...> wrote:
--
Expore all the Ideas...Exploit the good ones! |
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Re: First QSO with BITX17 !
Ron Brink
Dear Arv and Ruud,
Really appreciate your responses ! Yes, I am still puzzled by the results of yesterday. Will write some extra notes on my homepage to celebrate this " First Contact on 17 " event. Saw that my QTH-Zoetermeer near the Dutch coast?to Thessaloniki in Greece makes a 1920 km distance. Not bad with 5 (five) Watts RF.
Arv, I used the conventional Huff&Puff circuit (quite succesful I might say) as Klaas Spaargaren launched a couple of years ago. The circuitdiagram is on my BITX17-dedicated-webpage:? --> zenders (tx) ---> BITX17. Also visible?in the photo-folder of this group (PA2RF).
But when Hans has completed the minimalist (2 ic) huff&puff kit I really would like to try that circuit. It is a great design I think.
Will see if I can make some new contacts this afternoon on 17m. 17:00 utc seems to be a good time now in Holland to make some qrp (semi)dx !
But now I go bicycling with my children, the weather is great now in Holland, clear blue sky and 18 degrees C. Not a good idea to stay inside near the soldering station...
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73 de Ron
PA2RF
Arv Evans wrote:
Do you Yahoo!? Yahoo! Mail - 250MB free storage. |
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Betr: First QSO with BITX17 !
Hi Ron,
Congratulations with your first QSO! You experience the same excitement as I did with only 5 watt digital CW on 20 meters. This is really amateur radio! Lots of fun. 73 Ruud PE2BS -- Oorspronkelijk bericht -- _____________________________________________________________________ Je eigen persoonlijk e-mailadres bij Tiscali? Registreer nu een domeinnaam bij Tiscali. Ga naar |
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New file uploaded to BITX20
Hello,
This email message is a notification to let you know that a file has been uploaded to the Files area of the BITX20 group. File : /BITX 20 V1,2&3 /palayout.pdf Uploaded by : vu3wjm <vu3wjm@...> Description : Linear board with PSU and switching You can access this file at the URL: To learn more about file sharing for your group, please visit: Regards, vu3wjm <vu3wjm@...> |
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VU BITXers
Rahul Srivastava
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