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Hi Fellows This is only a prototype to work with a PCB. I have the file with the Sprint layout from ABACOM. Any concern about the design please forward to-Heriberto- cl2kmk@... ?? Qrv's 73's Jc
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It looks good! If it were mine I would change tow minor things. The resistors I would show as 4K7 for 4.7 because my old eyes have trouble with those little tiny decimal points any more, and I would leave a bit more copper showing around the mounting holes to make sure the stand offs have a good contact area. Jeff N9ARZ
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You might need a more solid ground plane. ?Perhaps stitch some of the islands on the backside together using traces on the front side. ? You are using 1n4148's in the mixers, Farhan is using BAT54 dual shottky diodes. ?The shottky diodes don't need as much drive from the bfo or vfo as the 1n4148's do. ?Also, the two shottky diodes in the balanced modulator are guaranteed to be balanced, not so for two randomly chosen 1n4148's. Looks like you have a totally different final amplifier. ?Farhan's push-pull IRF510's reduce the second harmonic, your single 2SC1971 may require more output filtering than Farhan's did. ? Farhan's initial schematic showed lots of BC849's, but only because he didn't have a decal for 2n3904's. ?His current schematic shows 2n3904's.
On Fri, Apr 7, 2017 at 06:42 pm, JuanCarlos Berberena Gonzalez wrote:
Hi Fellows This is only a prototype to work with a PCB. I have the file with the Sprint layout from ABACOM. Any concern about the design please forward to-Heriberto- cl2kmk@... ?? Qrv's 73's Jc
?
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Nice work, Jc.
I can see this as being easily made with automated equipment, but...
that's a lot of holes to drill at home. And all of them have to be precise.
Is it possible that a muppet style of board would work? I wonder since there are
so many traces on the bottom of the board... Maybe a more modular set of muppet boards?
Any idea of the production cost of this board?
john
AD5YE
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I agree that a Muppet board would be a great way to go, since it moves away from drilling holes. The only way I've had any success with thru-holes was when a friend availed his drill press for me to use. Plus, I went through drill bits like crazy...probably not the best bits and I seem to lack the patience for slowly drilling holes. Also, depending on how the board is laid out, you could use SMD's or standard components. Finally, you could have a thru-hole board manufactured. I've done this with the Forty-9er and antenna analyzer project and if you have enough boards done, the cost isn't that bad.
Jack, W8TEE
From: John Backo via Groups.Io <iam74@...>
To: [email protected]
Sent: Friday, April 7, 2017 11:39 PM
Subject: Re: [BITX20] uBitx Prototype (PCB)
Nice work, Jc.
I can see this as being easily made with automated equipment, but...
that's a lot of holes to drill at home. And all of them have to be precise.
Is it possible that a muppet style of board would work? I wonder since there are
so many traces on the bottom of the board... Maybe a more modular set of muppet boards?
Any idea of the production cost of this board?
john
AD5YE
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OSHpark is the best I've seen on small runs: ? For $5 per square inch, you get three double sided boards with soldermask and silk at 6 mil design rules. ?The BItx40 at 4.5x5 inches would cost $5 * 4.5*5 = $112.50, or $37.5 per board. ?But the bidi amps are one square inch each, so could get three of them for a total of $5. Could go to 0805 or 0603 or 0402 parts to drastically reduce the size of the Bitx40 (or uBitx). ?Take a look at 0201's if you are especially cheap and masochistic, but then you'll want access to a good binocular microscope.
On Sat, Apr 8, 2017 at 06:56 am, Jack Purdum wrote: Finally, you could have a thru-hole board manufactured. I've done this with the Forty-9er and antenna analyzer project and if you have enough boards done, the cost isn't that bad.
?
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The cost of what I call Beta Boards is pretty high, as Jerry points out. However, once the design is set, the costs fall dramatically. I ordered 200 small boards (2"x3") at about $1 each for a recent project. These were similar to the quality seen in the Forty-9er assembly manual (www.farrukhzia.com/k2zia). I would think that boards made for SMD's would cost less, but I don't know as I have not purchased any.
Jack, W8TEE
From: Jerry Gaffke via Groups.Io <jgaffke@...>
To: [email protected]
Sent: Saturday, April 8, 2017 11:03 AM
Subject: Re: [BITX20] uBitx Prototype (PCB)
OSHpark is the best I've seen on small runs: ? For $5 per square inch, you get three double sided boards with soldermask and silk at 6 mil design rules. ?The BItx40 at 4.5x5 inches would cost $5 * 4.5*5 = $112.50, or $37.5 per board. ?But the bidi amps are one square inch each, so could get three of them for a total of $5. Could go to 0805 or 0603 or 0402 parts to drastically reduce the size of the Bitx40 (or uBitx). ?Take a look at 0201's if you are especially cheap and masochistic, but then you'll want access to a good binocular microscope.
On Sat, Apr 8, 2017 at 06:56 am, Jack Purdum wrote: Finally, you could have a thru-hole board manufactured. I've done this with the Forty-9er and antenna analyzer project and if you have enough boards done, the cost isn't that bad.
?
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I use?. I did a quick quote for a board the size of BitX and it works at $62/5 boards sipped to Canada by DHL. I use them for all my boards needs as they have a regular price of $10/10 boards no bigger than 100X100 mm plus shipping. I am a cheap bastard so I choose shipping by HK mail and it brings the cost to $23/set. Now the boards can have multiple layouts on them. For my PCB design of the BidiAmp I can fit 4 of them on each board so 40 BidiAmps PCBs for $23 if you wait 3 weeks or 40 PCBs for $35 and you have them in about 10 days. The quality is very good and they are running right now a promotion, so 10 boards for only $5, or $18 shipped regular post, or $30 shipped DHL.
--
Ion VA3NOI
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I may use PCBWAY at some point. ?Good prices, and they claim 4 and 4 mil design rules. ? I use OSHpark when it makes sense, as they manufacture here in the US for a nice quick turn, produce beautiful boards with an ENIG finish, and have a very nice web interface for submitting gerbers. ?Many of the PJRC boards go through OSHpark. ?If only doing a few square inches on some prototype boards, it doesn't make sense to wait a month. ?
On Sat, Apr 8, 2017 at 03:12 pm, Ion Petroianu wrote: I use?.
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Though I now see Ion's mention that PCBWAY is pretty quick too: ? > or 40 PCBs for $35 and you have them in about 10 days.
On Sat, Apr 8, 2017 at 03:44 pm, Jerry Gaffke wrote:
If only doing a few square inches on some prototype boards, it doesn't make sense to wait a month. ? ?
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Jerry, We use them for business too. Their quality is very good. They have 24h service and you add DHL to that. For that there is a price to pay, but, in the office, we don't care about that. --
Ion VA3NOI
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If you’re comparing prices from different , check out http://PCBShopper.com. You enter your board’s specs, the quantity you want and how fast you want it, and it shows you prices from 25 different manufacturers including Dirty PCBs, Seeed Studio and the best known manufacturers in Asia, North America and Europe.
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hi
is your pcb all thru hole . what are the transformers , somebody has suggested 10 turns on ft37-43 is that right
terry gm4dso
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hi
what size is the board
terry gm4dso
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do you have gerbers for this project to have the board printed and a bom file ?
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Looks nice.??
Perhaps pin headers for audio derived AGC add on, pin headers for de click add on, pin headers for VOX add on.
Nice to have test points, I make them with a filled pad and silk circle+"TP1 (etc).??
Consider adding 2.54mm pin fields for power and ground and be certain that all power and ground islands are well stitched together.
As to the audio output stage.? Consider adding header pins for pwr, gnd, in and out.??
The builder could provide the choice of amplifier type or install the TDAxxxx part.
Several Chinese offerings?
here is one https://www.banggood.com/10Pcs-XPT8871-5V-5W-1A-Single-Channel-Mono-Digital-Audio-Amplifier-Board-p-1268826.html?rmmds=detail-left-viewhistory__3&stayold=1&cur_warehouse=CN??
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5W? 5V? digital mono. uses the XPT8871 IC (SIMILAR TO LM4871).
Amp has typical 3dB point of ~350 Hz and ~90kHz..? suitable for voice.
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?10 assembled amps from Banggood for $5.31 USD shipping included.? Amp has typical 3dB point of ~350 Hz and ~90kHz..??
I agree with the use of contemporary component value protocol.? Where 4N70 denotes 4.7nF,? 33R0 is 33 ohms, 331 is 330 etc.
73
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connections to copper islands. pads or areas where soldering is required that are not simple traces should be defined as a thermal (relief) pad.
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JuanCarlos Berberena Gonzalez
Jeff
Ion Petroianu, VA3NOI
Robert Ogburn