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About BITX PCB
Hello from EB1CPC / EC1ACV , in Spain. I try to build the BITX20. I have the PCB but I have many doubts about the location of many components in the PCB. Can anybody help me?. Anybody send me the
By Roberto Suárez <RADIO_EB1CPC@...> · #206 ·
Cap Meter and Freq Counter projects
HI Folks, I've just found this url in a newsgroup that may be of interest to someone out there :-) http://www.qsl.net/k1jhj Using AVR's in both projects, with free development software, free
By Mike W <mike@...> · #205 ·
IF filter passband measured
Hello, I have just uploaded a file with the results of my measurements of the IF filters passband. The set-up was a DDS-VFO as a signal source and a HF millivoltmeter as a detector.
By Heinz Schnait <oe5eep@...> · #204 ·
Re. problem with crystal oscillators
MILAREPA@............. It would appear from your chart that the higher frequency crystals may not be oscillating, or that your frequency counter may not be capable of counting above 10 MHz. Lets
By Arv Evans <arvevans@...> · #203 ·
Re: CRYSTAL MEASUREMENTS
Dear forum, ==About Crystal Measurements== At the time I mail to BITX about this subject, 'actually' I was using a 3.579545 MHz crystal, that available at my junkbox and drifting is in this
By MILAREPA <MILAREPA@...> · #202 ·
Archive message settings
Following a suggestion from Dave M1DGS I have enabled the group message archives for reading by non-members. This means that visitors to the group are now able to view all of our messages in the
By Hans Summers <Hans.Summers@...> · #201 ·
Re: Binocular Cores
Mike Some time ago (actually, many years ago) I remember reading somewhere that you can make up your own "binocular cores" by stacking two rows of conventional toroid cores. That's about all I
By Arvid Evans <arvevans@...> · #199 ·
Spam message
Hi Sadly it appears that a spammer has joined our group and sent a spam email which I received here at 1809 UTC. I have deleted the offending message from the messages archive, but those of you
By Hans Summers <Hans.Summers@...> · #198 ·
Measuring Crystal & IF Filter Frequencies
Hi Hans' comments (see below) are very appropriate to the measurement of Crystal frequencies. I too found that if you solder the crystals in place, it may be necessary to wait several minutes for
By Arv Evans <arvevans@...> · #197 ·
Re: CRYSTAL MEASUREMENTS
Your circuit and method look Ok to me... how bad is the drift, and what happens if you wait longer than 5 minutes? The drift could also be in your frequency counter (or PC if you are using that as a
By Hans Summers <Hans.Summers@...> · #196 ·
Re: BITX20 & BITX40
Hi Arv, Thanks a lot for the very detailed reply to my query and for offering to advise me on any problems I might face with building the trx. Knowing that I can bank on the group's knowledge and
By Bharat Balsavar <vu2bdx@...> · #195 ·
Re: Inexpensive plastic screwdriver
Paolo In the US, plastic knitting needles are available for an attractive price. These range from 1/8 inch to 1/2 inch diameter. The smaller ones are easily ground to a screwdriver point using
By Arv Evans <arvevans@...> · #194 ·
Re: BITX20 & BITX40
Bharat The discrete component AF Amplifier file is in the FILES and PHOTOS sections of the BITX20 forum on Yahoo.com You should be able to view and copy them from there. If you have problems please
By Arv Evans <arvevans@...> · #193 ·
Binocular Cores
I have found a 'source' of minature binocular balun cores in old UHF TV tuners and computer UHF modulators. there are usually, it appears, one or two per tuner. Not tried them yet though. atb Mike
By Mike W <mike@...> · #192 ·
CRYSTAL MEASUREMENTS
Dear forum, I try to measure my 12 MHz IF-crystals with method here, for purpose selection within 30 to 50 KHz ( is this value right ? ). But the problem is: Frequency reading is still moving /
By MILAREPA <MILAREPA@...> · #191 ·
Re: Inexpensive plastic screwdriver
Hi Paolo, I cut/filed a piece of PCB to the right size and sanded of the copper. The slight advantage over a toothbrush is that the material is less soft, so it can handle screws that are tight or
By Hubert Smits <hubert.smits@...> · #190 ·
Re: Inexpensive plastic screwdriver
Mike W wrote: WOW! Got to ask my mother if she has some spare plastic ones! For those non-native English speakers that might wonder what a "knitting needle" is, see the description here
By Paolo Cravero as2594 <pcravero@...> · #189 ·
Re: Inexpensive plastic screwdriver
Whats wrong with the old plastic knitting needle ?. When playing with HV circuits they are a lot longer and therefore safer. Another useful tool is a tuning wand, brass ferrule on one end of a
By Mike W <mike@...> · #188 ·
Relay question Help!
Hi! I recall reading about the two relay placement being helpful in avoiding RF pickup. I would be obliged if the someone will give me the new configration. 73 Rahul VU3WJM
By Rahul Srivastava <vu3wjm@...> · #187 ·
Re: Inexpensive plastic screwdriver
Hi! I fashion them out of glass epoxy PCB material. Much scrapped double sided PC boards are available.. cut a strip from area without copper traces ie normally the edges . File and shape the strip
By Rahul Srivastava <vu3wjm@...> · #186 ·