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Re: uBITX Questions
I gave those a value of 0, to indicate that those capacitors are not needed.? That said, i havent found time to update the circuit, essentially, the new version uses four LPFs instead of two, a 45 mhz crystal filter in place of the LC band pass filter. I has posted the new schematic a few months ago. I cant seem to locate it now. There was a problem with the LC band pass filter, the 14 and 10 mhz signals are just 2 mhz from the 12 mhz IF. When operating in these bands, the tx output was looping back into the second mixer, creating weird spurs. One way to avoid it is to separate out the PA board from the rest. the other way, which i have adopted, is to use a narrower crystal filter. These filters are easily available for less than a dollar as 45m15a or 45m15b. They are commly used in cordless phones and vhf or uhf handies. - f On 5 Oct 2017 5:44 am, "Dexter N Muir" <dexy@...> wrote: I'm not going to regurgitate the whole of this thread here, Jerry, but will offer this: I reply online, and refrain from the tedium of cut-and-paste for context. I haven't tried it here, but on Facebook I can highlight the material I respond to and it's auto-included. That's easy if I reply to the emailed Digest in the mailer, but less immediate so the less preferred option. And as before, those few seconds' consideration can avoid 'foot-in-mouth' disease. Besides, your reaction triggers my 'follow it to resolution' response (life imitating art, check "The Good Doctor") so this has become more than an 'aside' and should be elsewhere than this forum. |
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Re: Bitx20V3b/3c - Need Part Information for L1-L3
Yes -- they used to have them. They are listed under Audio/Signal Transformers.
There is presently no stock, and I doubt they will have any more. And yes, Mike, no one is making analog FM radios any more. Now they are all radios on a chip which are conveniently transported while jogging and have a range just about to the urban limits with megawatt FM transmitters! Hi. Good luck finding any. Everybody is looking for them. I have a few left, but after that...who knows? john AD5YE |
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Re: Bitx20V3b/3c - Need Part Information for L1-L3
¿ªÔÆÌåÓý
On 10/4/2017 6:53 PM, Ted Doell wrote:
-- Mike Hagen, WA6ISP 10917 Bryant Street Yucaipa, Ca. 92399 (909) 918-0058 PayPal ID "MotDog@..." Mike@... |
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Re: Bitx20V3b/3c - Need Part Information for L1-L3
¿ªÔÆÌåÓýMouser have them they are listed under audio transformers, but the data info tells you what they are 10 mins ago they showed over 2000 in stock. Ted ZL1BQA
On 5/10/17 2:14 PM, Michael Hagen
wrote:
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Re: Bitx20V3b/3c - Need Part Information for L1-L3
¿ªÔÆÌåÓýThese FM Radio IF Transformers used to be at
Mouser, I bought them. Maybe have 5 or 6 in a plastic box? They dropped them now, called obsolete? So no one must be making FM radios that used these? I guess you make your own now? Mike, WA6ISP
On 10/4/2017 6:06 PM, John Backo via
Groups.Io wrote:
These are 10 MHz IF filters. You should be able to find them somewhere, even in an old FM radio. Sunil will most likely send you the parts if you let him know. The BITX parts are IF transformers made in India. They are not the sturdiest parts in the world, and are prone to breakage. Warning: Fragile Parts! Another option is to examine and follow the example given in the BITX20A documentation, That filter is built from toroids, caps, and variable caps. It works as well as anything else. You can also build your own BPF using any of the many available online methods. Or, if you can find them, use the 42IF123 transformers. They are the best. Just remember in any event to remove the capacitor across the windings before you add another cap according to the schematic. Generally speaking, any transformer with about 5-6 uH on the main winding and 1-2 uH on the small winding will do. I have used all the methods in several builds, and the 42IF123 parts are the best, followed by a good rendition of the BITX20A method. john AD5YE -- Mike Hagen, WA6ISP 10917 Bryant Street Yucaipa, Ca. 92399 (909) 918-0058 PayPal ID "MotDog@..." Mike@... |
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Re: Bitx20V3b/3c - Need Part Information for L1-L3
These are 10 MHz IF filters.
You should be able to find them somewhere, even in an old FM radio. Sunil will most likely send you the parts if you let him know. The BITX parts are IF transformers made in India. They are not the sturdiest parts in the world, and are prone to breakage. Warning: Fragile Parts! Another option is to examine and follow the example given in the BITX20A documentation, That filter is built from toroids, caps, and variable caps. It works as well as anything else. You can also build your own BPF using any of the many available online methods. Or, if you can find them, use the 42IF123 transformers. They are the best. Just remember in any event to remove the capacitor across the windings before you add another cap according to the schematic. Generally speaking, any transformer with about 5-6 uH on the main winding and 1-2 uH on the small winding will do. I have used all the methods in several builds, and the 42IF123 parts are the best, followed by a good rendition of the BITX20A method. john AD5YE |
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Bitx20V3b/3c - Need Part Information for L1-L3
I ordered a Bix20V3b parts kit from India. Unfortunately, the kit was missing the metal coil inductors L1 through L3 that are used in the bandpass filter section ov the Bix20 Version 3 b/c boards. The bill of materials do not have a good description of these parts. Does anyone know the part information/vendor for these parts or any useful information to allow me to second source these parts? Thanks in advance, 73,? Chris w0anm |
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Re: uBITX Questions
I'm not going to regurgitate the whole of this thread here, Jerry, but will offer this: I reply online, and refrain from the tedium of cut-and-paste for context. I haven't tried it here, but on Facebook I can highlight the material I respond to and it's auto-included. That's easy if I reply to the emailed Digest in the mailer, but less immediate so the less preferred option. And as before, those few seconds' consideration can avoid 'foot-in-mouth' disease. Besides, your reaction triggers my 'follow it to resolution' response (life imitating art, check "The Good Doctor") so this has become more than an 'aside' and should be elsewhere than this forum.
73 de ZL2DEX |
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Re: uBITX Questions
Vince is right on this one.
toggle quoted message
Show quoted text
If it's not worth 3 seconds of your time to include a few bytes of context when needed,? it's certainly not worth 3 minutes of my time to ferret it out. Nor that of the 1000 other potential readers of this forum. I simply ignore such posts. On Wed, Oct 4, 2017 at 02:49 pm, Dexter N Muir wrote:
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Re: Function Button with Allard Munters code (v1.24)
#bitx40help
check the condition of the Fun switch.? Check the switch is actually "normally open" re check for resistance in the open state.? Or replace the switch.?? ?Re-seat the LCD Check where the connection is soldered in at the DDS for solder bridges. (ground) Check the DDS PCB component/wafer connections solder junctions. Maybe check for stray wire on the Tune pot shorting or cat "whiskering"....replace the pot with the kit supplied tune pot.? I've had the blue 10k 10T pot go out already open internally. Early indication is the pot turns roughly towards the end of life. On Mon, Oct 2, 2017 at 5:04 PM, <robert.m.cox@...> wrote: Hi -? |
Goran VE6GPO
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