Re: Bitx Delivered..YAY!!
Mine too : ordered 15-12, it arrived through India Post to day.
73 - Jean F5PCX.
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Re: MAX9814 mic preamp and DC bias capacitor
So, mic gain control for the win.
Thanks Mike!
Marco - KG5PRT?
On Jan 30, 2018 11:04 AM, "Michael Hagen" < motdog@...> wrote:
I put a 1K to a 2K pot
to ground.? Take the output to your capacitor from the wiper.
You can adjust all the
way to ground (nothing out).
73's
Mike, WA6ISP
On 1/30/2018 8:33 AM, M Garza wrote:
Could I change R64 to a 220 ohm resistor?? I think
1k is too high.? I am using the max9814 on 40 dB and it is way
too much.
Thanks,
Marco - KG5PRT?
--
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID "MotDog@..."
Mike@...
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Re: IRF510 amplifier failures
We have thousands of uBitx's and Bitx40's out there now, an occasional post to the forum about? a blown IRF510 is inevitable My opinion is that SWR is not what blows the IRF510's, especially when operating from 12v. Biggest issue is that the heatsink is quite small, especially if operating continuous duty in some digital mode and/or feeding the IRF510's more than 12v to get higher power. Also, be aware that the gate bias adjustments are backwards (clockwise is minimum), and get very touchy as you approach the transition region, so once the drain current starts going up it is not much of a turn? to go from the optimal 100ma to a very hot IRF510 with 3A of drain current. And be aware that the heatsinks as shipped are not insulated from the IRF510 tab (connected to the drain). I'd guess most failures are due to overheating and messing up when adjusting for 100ma of drain current. A temp sensor and foldback current limiting would avoid these troubles if you want a safety net. Other failures due to screwdrivers in the works or flying leads touching the wrong spot and other such snafus. Reverse DC is not a problem for the IRF510.? It has an intrinsic reverse diode from source to drain, will blow the traces or coils between it and the power supply.? Or, with some foresight, the fuse you put into that power supply lead.? Where you need reverse protection is going into the remainder of the board, be it Bitx40 or uBitx.? A 1n4148 diode would suffice, a 1n400x would not get quite so hot, but there is no problem with running all that stuff at 0.7 volts less.?? Having a full wave rectifier in line with the power supply to the IRF510's would reduce the voltage there by 1.4 volts.? And have a significant hit on output power available. In post 22597, KB1GMX reports:
My experience with IRF510s is extensive and much different. ?I rarely kill one even during experimenting.? I use them for RF power though 6M. ?How much 8 in a parallel 4x4 push-pull at 6M running 225W! ?My favorite is two in a push pull amp (K500r/wa2eby design) with 28V running about 55W on 40m and 37W at 10M and after 6 years of wrong antenna and all sorts of usual havoc its still running with the same pair.?
So the IRF510 is capable of being worked very hard, and still surviving when driving a high SWR. Testing an antenna system with no more than 12v into the IRF510 should be fairly bulletproof. If you want to reduce power further, reduce the drive level to the final using R136 on the Bitx40, RV1 on the uBitx. Again, note that these pots work backwards, fully clockwise is minimum drive. Jerry, KE7ER
On Tue, Jan 30, 2018 at 04:54 am, John Brock wrote:
I have not received my uBitx yet. I¡¯ve been? reading this forum for about two weeks. Looks like PA failures is a huge problem.
Are the two main causes reverse DC power and high SWR?
For the DC polarity problem how about a full wave rectifier at the DC input? Two diode voltage drop a problem with this approach?
What would be the best way to limit PA? power out to a very small value to allow a manual tuner to be used for the SWR issue?
?
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Re: MAX9814 mic preamp and DC bias capacitor
I put a 1K to a 2K pot
to ground.? Take the output to your capacitor from the wiper.
You can adjust all the
way to ground (nothing out).
73's
Mike, WA6ISP
On 1/30/2018 8:33 AM, M Garza wrote:
Could I change R64 to a 220 ohm resistor?? I think
1k is too high.? I am using the max9814 on 40 dB and it is way
too much.
Thanks,
Marco - KG5PRT?
--
Mike Hagen, WA6ISP
10917 Bryant Street
Yucaipa, Ca. 92399
(909) 918-0058
PayPal ID "MotDog@..."
Mike@...
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Re: Cheap Harbor Freight Case for MBITX
I guess I'm lucky I have access to a water cutter. All I have to do is draw the template and give it to a friend of mine
On 29 Jan 2018 9:50 pm, "Vince Vielhaber" < vev@...> wrote: I've been working on a plastic one that fits both the Pelican 1150 and the Apache 1800.? I actually bought the Pelican without the pick-n-pluck.
I still need to thin it some since I found it can actually be used on the top as well if you're not putting anything real thick in it.? Some LCD displays will fit in the top with a plastic panel.
Vince.
On 01/29/2018 05:39 PM, Ken Hansen wrote:
This 'pelican-style' case is also nice - I'd love to figure out a front
panel that snaps over the bottom half of the case (remove all
pick-and-pluck)...
Ken, N2VIP
On Jan 29, 2018, at 3:47 PM, wishbone_aaa <dlmock@...
<mailto:dlmock@...>> wrote:
Just place my order for a MBITX and have been looking for an
enclosure. I spotted in my workshop a Harbor Freight plastic ammo box
that looks like it will do the job.? With the lid open, the box is 6
inches deep,9 3/4 wide and 4 1/2inches high.? Price $6.99 (even
cheaper when there's a coupon).
? <>
--
? Michigan VHF Corp.? ?? ?
? ? ? ? ? ? ? ? ? ? ? ? ?
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Re: Perfect speaker grill
Hi,
as speker grill, I have been using, in some projects, the italian moka coffee espresso spare filters,as the one reported in picture.
These are of different sizes, starting from 2 coffee cups up to 12 cups, as the one in picture. No sound problems.
The filter has a flange and it can be glued to the panel, or blocked by the speaker.
73
Gian
I7SWX
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Re: Inkits India QRP kits
?Wish I was more proficient with the programs needed to do all this I certainly would help. ?
On 30 Jan 2018 2:31 am, "Mike Woods" < mhwoods@...> wrote:
A great idea Alan
I have made the page template ... now the hard part in putting it
all together.? You don't want to volunteer do you?
A list of all products (WORD table you send me),? supplier,
website (if there is one) and email address for contact.
73
Mike
On 30/01/18 10:43 AM, Alan de G1FXB via Groups.Io wrote:
We need a who is who,
on the uBIX.net page.
So we easily know who is selling what:-
Raduino clones,
Improved Raduino's, Touchscreens, AGC, S-meter, Mic Amp, Speech
Processor, PA protection circuits, SWR Bridge, Auto ATU.
forgotten anything?
it's ALL TOO MUCH......? :-)
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Re: Second batch of uBITX shipping?
#ubitx
I know it took almost 3 months to get my novice license in the mail back in 1979 ;)? Sent from my iPhone
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Show quoted text
On Jan 30, 2018, at 11:07 AM, David Wilcox via Groups.Io < Djwilcox01@...> wrote: What about waiting for your ham license from the FCC? ?IN 1960 it took about six weeks, and there was no internet to look it up early.
Dave K8WPE On Jan 30, 2018, at 6:54 AM, Leland Lannoye < wa9aoe@...> wrote: So glad somebody remembers all those marketing gimmicks of Howdy Doody and Captain Video days. My grandson doesn't even know the difference between an and and an or gate. Perish the thought of knowing what a transistor does.
Sent from my Verizon, Samsung Galaxy smartphone
-------- Original message -------- Date: 1/29/18 19:49 (GMT-05:00) Subject: Re: [BITX20] Second batch of uBITX shipping?
Y'all are all so spoiled. I remember ordering from the back of comic books and cereal boxes and having to wait "allow 6-8 weeks for delivery" for my "Amazing X-Ray Glasses" or "Secret Decoder Ring". No email, no tracking numbers.? Just endless faith and optimism. And that was just from Kalamazoo? or Battle Creek Michigan. If you got it at all you were amazed! Tom
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Re: MAX9814 mic preamp and DC bias capacitor
Could I change R64 to a 220 ohm resistor?? I think 1k is too high.? I am using the max9814 on 40 dB and it is way too much.
Thanks,
Marco - KG5PRT?
On Jan 30, 2018 2:47 AM, "Raj vu2zap" < rajendrakumargg@...> wrote: Just decrease the value of R63 for more gain!
At 30/01/2018, you wrote:
>uBITX Mic Audio
>
>I think that the rig only needs slightly more gain in the existing Mic PreAmp.?? I believe adjusting values to add gain is really all that is needed.?? Don't need 40 dB extra gain.
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Re: #ubitx New I2C/Digital I/O mod & firmware from W0EB/W2CTX
#ubitx
OK jim excuse me ,but where have you find case for ?bitx? 73 jo?l f6cht.
i have not your email adress!!
toggle quoted message
Show quoted text
Le 30/01/2018 ¨¤ 16:24, Jim Sheldon a ¨¦crit?: OOPS,
you accidentally got some update code (lets go back to private email on this). you have my email address - I have a quick fix for this
Jim
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Re: Second batch of uBITX shipping?
#ubitx
What about waiting for your ham license from the FCC? ?IN 1960 it took about six weeks, and there was no internet to look it up early.
Dave K8WPE
toggle quoted message
Show quoted text
On Jan 30, 2018, at 6:54 AM, Leland Lannoye < wa9aoe@...> wrote: So glad somebody remembers all those marketing gimmicks of Howdy Doody and Captain Video days. My grandson doesn't even know the difference between an and and an or gate. Perish the thought of knowing what a transistor does.
Sent from my Verizon, Samsung Galaxy smartphone
-------- Original message -------- Date: 1/29/18 19:49 (GMT-05:00) Subject: Re: [BITX20] Second batch of uBITX shipping?
Y'all are all so spoiled. I remember ordering from the back of comic books and cereal boxes and having to wait "allow 6-8 weeks for delivery" for my "Amazing X-Ray Glasses" or "Secret Decoder Ring". No email, no tracking numbers.? Just endless faith and optimism. And that was just from Kalamazoo? or Battle Creek Michigan. If you got it at all you were amazed! Tom
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Re: [SPAM] Re: [BITX20] IRF510 amplifier failures
This is what current limiting to the final amplifier would do. It would make the final non-linear and generate all kinds of spurious products. Protecting the final with a fuse, be it resettable or a destruct type, would be far better.
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Re: uBITX woes, feeling disheartened.
#ubitx
Hi Nick,? I got the same relay and am equally confused as the pinout for both the original relay (Virtual) and this replacement (Panasonic) appears to be the same (across 1/16 on both pinouts); yet the schematic shows the coil across pin 8/9 per:?? /g/BITX20/message/40439Oddly, the data sheet for this relay which I posted here:? /g/BITX20/message/40440? is no longer available.?? Further, this post:?? /g/BITX20/message/26983? indicates coil across 1/16 also.? I'm going to disconnect PA power this weekend and use an ohm meter to trace through the relays per someone else's suggestion.?? Dave -- Dave Beal AE6RQ
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Re: IRF510 amplifier failures
Same here have a bitx40 that's run all mode pretty much stock on the PA side never even adjusted the bias. I have messed with the gain a bit, that is about it still stock heatsink too.
The things to keep in mind: It's qrp don't push it and for digi modes 1/2 the power to be safe and not stress the IRF510. I have worked the world on digi modes under 5w.
I also run a WA2EBY with 2 510's other than some heat they run just fine.
I have not seen to many under "normal" operation blow unless its part failure from a manufacture defect or operator error.
At QRP levels (5-10w) the 510 can take the heat its when you push them north of 40-50W where SWR and heat become something to pay attention to.
--
David
?N8DAH
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Re: #ubitx New I2C/Digital I/O mod & firmware from W0EB/W2CTX
#ubitx
OOPS,
you accidentally got some update code (lets go back to private email on this). you have my email address - I have a quick fix for this
Jim
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Re: UHF/VHF uBITx equivalent
Thank you sir! I had just stumbled across this last night as well. While not a full home-brew as you call out, it certainly can be a cool project to work on with my kids!
On Mon, Jan 29, 2018 at 11:40 PM, Ashhar Farhan <farhanbox@...> wrote:
But, this is not much of a homebrew. The challenge would be to build something from scratch.
- f
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Re: UHF/VHF uBITx equivalent
I have a UV5R. 2 actually, LOL. It's not as fun as building something, even if it's from a kit, though.
Building helps me to gain a deeper understanding of the technology and I can go over it with my kids and teach them along the way.
Looking forward to what you come up with!
Fred
KC3HMS
On Mon, Jan 29, 2018 at 11:26 PM, <nickpullen@...> wrote: Hi Fred.
This is also on my project list. I have both the V and U version of the DRA818. I am planning on a simply desktop unit powered by arduino and a nokia 5110 lcd.
a cheap baofen mic/speaker. Just for experimentation and local repeater access as these modules are only 1W... maybe even do APRS...
In the end though, If all you want is a cheap V/U radio, just buy a $30 UV5R...
73, Nick. VK4PLN
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Re: Bitx Delivered..YAY!!
And me. Ordered on 15/12 and it's just arrived in the UK, s/n 368/2.
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Re: Second batch of uBITX shipping?
#ubitx
On 01/29/2018 07:49 PM, Thomas Noel wrote: Y'all are all so spoiled.
What's the point of even HAVING an internet connection if you can't fret, rant, and worry things to death? :D I remember ordering from the back of comic books and cereal boxes and having to wait "allow 6-8 weeks for delivery" for my "Amazing X-Ray Glasses" or "Secret Decoder Ring".
No email, no tracking numbers.? Just endless faith and optimism.
And that was just from Kalamazoo? or Battle Creek Michigan.
If you got it at all you were amazed!
Those WERE the good old days, weren't they? Nowadays it's instant this and priority that and two days from the Asteroid Belt to your doorstep! 6-8 weeks would probably be about right. I ordered mine 12/30. Two weeks ago I was told it would be about three weeks 'til it shipped, which ought to put it on my front porch between 6-8 weeks from when I ordered. :D -- ------------------------------------------------------------------------ Bruce H. McIntosh bhmcintosh@... www.afn.org/~scotsman WA4UF ------------------------------------------------------------------------ Network geek with a strong affinity for Telecasters
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Re: Bitx Delivered..YAY!!
Same here ordered 15 Dec and sn 361/2 Sent from my iPhone
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On Jan 30, 2018, at 9:33 AM, Alex Champkin < achampkin@...> wrote: Mine here too, ordered 15th Dec and arrived today. Board 360/2. Looking forward to getting it into a case.
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Art Howard
Giancarlo - I7SWX
Joel Fournol
N8DAH
Jim Sheldon
mrz80