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Re: 13.8 v power supplies safe for bitx?
Jack Purdum
I have a solar system that tracks the sun using a NEMA 17 stepper motor and an Arduino. A small 10W panel works through a controller to supply juice to a battery: In this case, the battery is a small motorcycle battery. I have since trade it out for a small lipo pack. Jack, W8TEE From: Don Meyerhoff <wa2swxdm@...> To: [email protected] Sent: Wednesday, March 14, 2018 3:50 PM Subject: Re: [BITX20] 13.8 v power supplies safe for bitx? I use one myself. Works great. Piece of mind for a couple of bucks. 73 Don Meyerhoff WA2SWX On Mar 14, 2018 3:47 PM, "Walter" <W9KJO@...> wrote: This is all good and important information.? My solar power system will bring my batteries up to 14.6VDC for about an hour every day.? My system normally runs art 13.4 VDC.? Usually the battery conditioning occurs while I am at work.? However when I am off work I may actually be operating when this battery conditioning is taking place.? I may need to think about putting a regulator in the case to manage this.? |
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Re: RD transistors, unobtanium?
M Garza
I am confused.? Looking at this page:?? RF Parts still lists this as available. Marco - Kg5PRT On Wed, Mar 14, 2018 at 2:45 PM, Ashhar Farhan <farhanbox@...> wrote:
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Re: 13.8 v power supplies safe for bitx?
Had never heard of Drok, they have lots of stuff up on Amazon.
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Does your Drok allow you to set the max current anywhere from 0 Amps to say 5 Amps? Sorely needed. Lots of cheap switchers out there now, but none of them seem to deal properly with current limiting. Should be able to set both the regulated voltage and the max current. If the load sucks too much current, the voltage drops until the current comes within the set limit. Any of those switchers could do this for the price of an op-amp and a pot, maybe an extra $1. Jerry, KE7ER ? On Wed, Mar 14, 2018 at 12:47 pm, Walter wrote: A little more expensive model put out by droke even has a current limiting feature. |
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Re: 13.8 v power supplies safe for bitx?
Don Meyerhoff
I use one myself. Works great. Piece of mind for a couple of bucks. 73 Don Meyerhoff WA2SWX On Mar 14, 2018 3:47 PM, "Walter" <W9KJO@...> wrote: This is all good and important information.? My solar power system will bring my batteries up to 14.6VDC for about an hour every day.? My system normally runs art 13.4 VDC.? Usually the battery conditioning occurs while I am at work.? However when I am off work I may actually be operating when this battery conditioning is taking place.? I may need to think about putting a regulator in the case to manage this.? |
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Re: 13.8 v power supplies safe for bitx?
This is all good and important information.? My solar power system will bring my batteries up to 14.6VDC for about an hour every day.? My system normally runs art 13.4 VDC.? Usually the battery conditioning occurs while I am at work.? However when I am off work I may actually be operating when this battery conditioning is taking place.? I may need to think about putting a regulator in the case to manage this.?
I think I will use a regulator similar to a boost regulator (link below) that I use in my ham station to charge my laptop.? These produce no RF noise, at least in my use they haven't, and provide a stable regulated voltage.? This model is only about $6.00.? A little more expensive model put out by droke even has a current limiting feature.? I have some of those too.? This will likely be my solution to limiting the DC power to my UBITX on my solar power system. Thanks for the great information -- 73, W9KJO Walter |
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Re: Ubitx audio debug question
I'm curious what maker's mark you find on those new chips from Gateway,
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and how well they work for you. Seems to be a half dozen different flavors out there. Some of the clones are kind of sour, as you have noticed. On Wed, Mar 14, 2018 at 11:52 am, <WA9GQT@...> wrote: Thanks Jerry, |
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Re: Digital BFO Mod: Terrible Audio!
#bitx40help
Hi Jerry and Allard,
I was hoping you two would chime in. I chose the uBITX sketch for several reasons: 1) already has band switching 2) already has rotary encoder 3) already has BFO 4) wanted the challenge of making it work on an Uno R3 and i2c LCD. I *think* I have the nuts and bolts of all those things correct but I'm just missing something somewhere else. I'll do a bit more testing and possibly a video to describe it, and get back to you. -- Ryan Flowers - W7RLF |
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Re: more cases
Vince Vielhaber
No, I tried to find info on what it actually is but all I found was ebay listings. Didn't bother looking at them.
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Vince. On 03/14/2018 01:59 PM, Roy Appleton wrote:
Any clue as to the inside dimensions of these? --
Michigan VHF Corp. |
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Re: Ubitx audio debug question
What was the logo on the fried U1?
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Does it? say "WX TDA2822"? Does it say "FCI TDA2822"? This is important. I suspect that a good TDA2822 will not fry with a short unless you have the volume turned way way up. And that you have the WX clone. But I could be wrong. Here's the latest news regarding the bad chips: ? ??/g/BITX20/message/44394 ? ?? You can probably find an LM386 locally or in some older project that can be hacked in there temporarily till you get a new TDA2822 in from Mouser or Tayda or similar. Choosing a $109 all HF band SSB transceiver means you get to deal with this sort of thing. Jerry On Wed, Mar 14, 2018 at 10:31 am, <WA9GQT@...> wrote:
I was very cautious and finally got the uBITX?wiring correct after looking at all the posts.? It was receiving great until I unplugged my headphones and |
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Re: Complaint Department
Like I say, a wiki would have a lot of competing firmly held opinions.
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You are correct, if the primary use of that jack is to plug in an external speaker. A builder that always uses stereo headphones is best off with tip and ring wired together, plus the series resistor. Both options could be presented in that addenda, with an explanation of the pros and cons for each. Including a warning that a mono plug will result in no audio if the jack is wired for stereo. On Wed, Mar 14, 2018 at 10:43 am, Vince Vielhaber wrote: I'm referring to the wiring diagram. It still has the tip and ring connected together. A mono plug WILL short it out. 8 ohms in series or not, plugging in a mono plug will result in no audio, regardless if the 2822 blows. No audio = unhappy builder. Nowhere in the wireup does it say not to use a mono plug. But it does say, "The brown wire has to be connected to the (both) the tip and the ring of the headphone socket." |
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Re: more cases
Any clue as to the inside dimensions of these? Roy WA0YMH On Mar 14, 2018 12:53 PM, "Vince Vielhaber" <vev@...> wrote:
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Re: Raduino oscilators. 33mhz and 57mhz. Documentation says one thinng, but this is what I measured.
Here's a current and more complete summary of what's going on with the uBitx.
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For the few who really really want to know. Not many, judging from the response to post 44278. Actual frequencies used in the original uBitx code are to have clk0 (bfo) fixed at 11996500 hz, maybe 500hz below the 12mhz filter's 2000 hz wide 3dB passband. Oscillator clk1 (second local oscillator) is fixed at 56995000 hz for USB and 32995000 hz for LSB. You can find those three numbers in file ubitx_20.ino at lines 166, 163, 164 respectively. I'm looking at the version dated Dec 6, 2017:??? ?? The vfo is used to select the operating frequency Fop according to these formulas. For USB:? ? Fop? = vfo - (clk1-bfo)? ? ? ?so? ? vfo = Fop + (clk1-bfo)? ? ? ?where clk1 is around 45mhz+12mhz For LSB:? ? Fop? = vfo - (clk1+bfo)? ? ? ?so? ? vfo = Fop + (clk1+bfo)? ? ? where clk1 is around 45mhz-12mhz To receive a 7.2mhz LSB signal (where 7.2mhz is the frequency of the suppressed carrier), the VFO gets set to? ?7200000+(32995000+11996500) = 52191500 hz. That formula gives an exact result, not an approximation. Regarding USB vs LSB: The BFO corresponds to the carrier frequency of the station being received or transmitted. The 12mhz filter is always above the BFO, so within the 12mhz IF it allows through only the upper sideband. The VFO is always above the 45mhz first intermediate frequency, and so always inverts the sidebands: ? ? A carrier at 7200000 would get translated to vfo-Fop = 52191500 - 7200000 = 44991500 hz ? ? A lower sideband at 7198500 would get translated to 52191500 - 7198500 = 44993000 hz In this example we assume the lower sideband is generated from a single audio tone into the mike of 1500 hz. I have chosen 1500 hz because it will land in the middle of the 12mhz filter's passband,?assuming the filter has a 3 dB passband that's 2000 hz wide and the BFO is 500 hz below that passband. The actual range of frequencies passed will be 500 to 2500 hz. Those assumptions of 2000 hz and 500 hz might be off by a couple hundred hz. Likewise, a high side clk1 of 56995000 hz? for USB always flips the sidebands when translating to 12mhz, however the low side clk1 of 32995000 hz we use to receive the 7.2mhz LSB signal does not: ? ? Our 7.2mhz carrier:? ? 44991500 - 32995000 =? 11996500 hz? ? (exactly equal to our BFO frequency) ? ? Our 7.2mhz lower sideband:? 44993000 - 32995000 = 11998000 hz? (in the middle of the crystal filter passband) That's how the original uBitx code works. I believe there is a problem because where an LSB signal hits the 45mhz filter will be 4khz removed from where a USB signal hits it, resulting in a different audio quality between the two. A solution to this is found in post 44278, review the previous posts in that thread to see why. Even with the fix, there will be differences in the audio unless the 45mhz filter response is flat across the 2000 hz at the center. Jerry, KE7ER On Wed, Mar 14, 2018 at 09:07 am, Michael Shreeve wrote:
Thankyou Jerry for trying and fairly successfully explaining what Ashhar is doing by using the ACTUAL frequencies used in the uBITX. |
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more cases
Vince Vielhaber
Two ebay auctions ending in a couple hours. These look like good cases AND they have power supplies built in. Also looks like the display opening may be the right size. They also have turns counter dials in case you are putting a B40 in it with a 10 turn pot! I thought about bidding on both but I'm trying to get rid of stuff, not add to it.
Note: One auction is for 2 cases and the other is for 3. No relation to the seller, of course, except that I've bought from them before. Vince. -- Michigan VHF Corp. |
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Re: Complaint Department
Vince Vielhaber
I'm referring to the wiring diagram. It still has the tip and ring connected together. A mono plug WILL short it out. 8 ohms in series or not, plugging in a mono plug will result in no audio, regardless if the 2822 blows. No audio = unhappy builder. Nowhere in the wireup does it say not to use a mono plug. But it does say, "The brown wire has to be connected to the (both) the tip and the ring of the headphone socket."
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Vince. On 03/14/2018 12:24 PM, Jerry Gaffke via Groups.Io wrote:
Here's where that addenda needs to be curated, --
Michigan VHF Corp. |
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