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Re: Power supply for the transceiver
I decided to check the current draw of my 49er in the Xmit position. With a steady 3 watt out and key down, current drain from my old Heath DC bench supply was 860mA.
Conditions: ? Power out: 3w Vcc: 13.85V? VSWR: 1:1 into 50 ohm, non-reactive load? 1-3/4(L) x 3/8(H) x 1/8(D) Alum. heat sink 2.5 ohm?emitter?resistor (reported earlier) D882 data sheet lists maximum DC collector current as 3 Amps! ... you better have a massive heat sink on that collector if you intend to leave key down for any length of time with that load. ? Jim, ?AB1BR |
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Power supply for the transceiver
I thought about how to power the transceiver and found a nice solution that probably others have seen but perhaps not pointed out. ?There is a cable for sale on eBay that contains the electronics to go from usb to 12 volts and I picked one up for $1.68. ?It is rated at 750 ma and the current drawn by mine in the receive mode is 142 ma. ?I have not tested the draw when transmitting but if it does 3 watts like the construction article states, that would take the draw up by 250 ma for what would be a total of about 300 ma., well under the rated power. ?With this, my battery problem is simple. ? If you want to look at the cord, search for ?USB DC 5V to DC 12V Step-up Module Converter 2.1x5.5mm Male Connector ?WB6TOU |
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Re: Implementation of the voltmeter option
So I guess this begs the question...? What voltage is the right voltage??? I am currently powering my radio with a 2 cell 3000mAH 7.4V LiPo battery using a voltage up-converter.? So I can set the voltage to what I want. Currently I am running it at 13.5 with no ill effects.? I'm thinking higher voltage = higher output power... Your thoughts???? Brian |
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Q5 (D882) Issue
2.5 Ohm Resistor Stablizes Q5 Final... ? Noting D882's emitter is tied directly to ground, I thought it might ease Q5's burden to add a small power sharing/stabilizing resistor in the emitter leg. ? I cut the emitter lead short and wrapped it up along the transistor body (print side) allowing insertion of a?2.5 ohm,?1/2 w, 5% resistor between emitter and ground.? Now, as long as the VSWR is good, I can transmit a steady 3 watt signal while adjusting the tuner. There is less heating?at D882's collector because there's a small aluminium heat sink, but also, the small emitter resistor shares?some of the?power dissipation. ? ?...now to make my first contact. .. _ ? ? Jim - AB1BR ? |
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Re: Implementation of the voltmeter option
The latest version of the voltmeter implementation has been uploaded. Added feature is cautions and warnings when the input voltage exceeds certain triggers. You can edit those triggers by changing the #define definitions at around line 518 to suit your application. Also if you don't like the flash rate of the display you can change the rate at the definition just above the triggers definition. ? When the Arduino senses the voltage from the voltage divider going to pin 27 it then does a little calculation then displays the input voltage. When this voltage strays to say 12.5v the voltmeter will start to flash on then off every 750ms. If it strays further to say 12.8v then the voltmeter will start to flash on then off every 250ms. ? I chose this flash rate as it gave a balance between getting my attention and being annoying. For what it's worth there actually is a standard for these kind of things in the aviation world. The root document is from the US Department of Defense and calls for?a caution flash rate of 1 to 2hz. For a warning it is 3 to 5hz. In aviation it is meant to get your attention and be annoying so the pilot in command can take appropriate action. Tried the 'official' rates and it just didn't look right on the $2 displays we are using. Kept slowing it down till it did look reasonable at least to my eye. ? At this point I consider the voltmeter project completed. It's been a hoot dusting off some self taught skills from 20 plus years ago. Thanks for the soapbox to share with others. Now on to getting the Forty-9er soldered up. ? Till later Hank K5HDE |
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New file uploaded to SoftwareControlledHamRadio
Hello,
This email message is a notification to let you know that a file has been uploaded to the Files area of the SoftwareControlledHamRadio group. File : /vfo-source-rev6-volt-alert.ino Uploaded by : hankellis1958 <HankEllis@...> Description : Added input voltage cautions and warnings to the basic voltmeter implementation. To adjust the triggers for your application go to line 518 or thereabouts and edit the lines that start with #define. As it sits the voltmeter will start flashing at the rate of 750ms for a caution and 250ms for a warning. Adjust the #define line above the triggers definitions to what looks good to you. You can access this file at the URL: To learn more about file sharing for your group, please visit: Regards, hankellis1958 <HankEllis@...> |
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Re: Question of transmit freqency
That is because the 49er has a direct conversion RX...both side bands are received equally.? You need to determine which side is the correct one to listen to, based on the direction of the TX offset.? If that can't be determined from the documentation, then an easy way would involve using a separate transceiver to figure it out....but someone will probably chime in here! 73 de Lee -- On Jul 15, 2016 4:38 PM, "john.k@... [SoftwareControlledHamRadio]" <SoftwareControlledHamRadio@...> wrote:
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Re: connecting boards.
From: ab1br@... [SoftwareControlledHamRadio] ; To: ; Subject: [SoftwareControlledHamRadio] Re: connecting boards. Sent: Fri, Jul 15, 2016 2:54:54 PM
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Re: Software Upgrade
From: ab1br@... [SoftwareControlledHamRadio] ; To: <SoftwareControlledHamRadio@...>; Subject: [SoftwareControlledHamRadio] Re: Software Upgrade Sent: Fri, Jul 15, 2016 8:40:32 PM
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Re: Software Upgrade
It was declared--by Jack, I think--sometime ago, and I believe mentioned in the Arduino Nano programming instructions that come with Farrukh's PCB board, that the older IDE (rev.1.165) is used because I2C displays didn't play or weren't available in library when used with the newer IDE.?
I'm a arduee newbie, but suspect there are advantages in using the upgraded IDE. Perhaps the libraries aren't complete for the latest rev or not correct for the specific display used for the Nano DDS. ? Still trying to get my transmitter to stay on... ...Jim, AB1BR |
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Hang time from key down to recieve mod.
I have build the 49¨¦r, but have not ( yet ) the original Nano/DDS board avalible. I use another, similar, construction of a VFO and other software, and have made the 2 stage amplifier, on a vero board. And if works pretty good. But I have had som timing problems after releaseing the key to recieve; it took too long time! It is the time constant on the gate of Q1, that has to be changed in my case. I have replaced the capasitor CP9 ( 1uF) to a 47nF, and now I think it?s work perfect. 73 de OZ1QZ / John |
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Software Upgrade
I am trying to upgrade the software on the DDS to Rev 6.10.? Am having problem? with getting the? right LiquidCrystal_I2C.h file to work in the library.? I got this message when I tried to compile the program..?? I got an error on this line "?LiquidCrystal_I2C lcd(0x27, 2, 1, 0, 4, 5, 6, 7,3, POSITIVE);"? The error message is POSITIVE was not declared in this scope. Thanks for any help and advice |
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Re: connecting boards.
The 49er is not especially selective -- the passband is broad and the front-end can be over-loaded quite easily. This is why Jack designed the BCI filter; could it be, the CW operator you heard is in your neighborhood? Also, if you haven't, try going to 1KHz resolution tuning so you move more quickly up or down the band.
Jim AB1BR |
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Re: connecting boards.
For all those people having trouble with the wiring on the encoder, if you are using the info downloaded from the ARRL In-Depth website I suggest you stop trying to use that info.
Go to the Zia website mentioned in the March 2016 QST article and download both the building info and Nano software from that site.? There were corrections sent to the ARRL but I found they were not being updated in a timely manner and it caused me problem.? Also, you can use the software from this reflector for showing the input voltage on the display as it works very well. When I switched to the info from the Zia website and followed it the unit I built came up flying and worked exactly as described.? Caused me a lot of frustration with the same issues I've been reading about but the Zia website had the corrections and the rig is working just great. Mine puts out 3.5 watts and I also added the Hi-Per-Mite CW filter from the 4SQRP group plus the AA0ZZ keyer version 2. Turned out really nice and I have pictures of it in the photos section. Gary A. - W0MNA |
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Re: connecting boards.
Use a pencil carefully and follow the wiring on the schematic, comparing to the figures. Easy to goof for sure.
A simple VOM on AC mode will work. The output has both AC & DC levels. Assuming you have a receiver tune it to the 40 meter band and you will hear it. An antenna will bring in signals. Just joking. My earphone jack was defective, in that it only worked when I pushed the plug in partially. Hope that helps. 73 Bo W4GHV since 54 |
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Re: connecting boards.
Karl Schwab
I too, have questions on this same subject about the wiring between the 49-er and PCB board.? I assembled my?PCB board with the connecting pins for J2 and J3, exactly as pictured in the "QST in Depth - Purdum", pages 21 and 22.??The JPG photo that is shown in the previous post here, doesn't make that clear enough to me.? I know that if I am not exactly correct with my wiring, I will have all kinds of trouble!? To further simplify this, I would like to see a very detailed description of all wiring.? This may seem as a easy task for some of the builders here, but I want this build for me to be successful , right from the start!? Also, in lacking a oscilloscope, is using a HF probe ok to set R1 to the required 4 ~ 4V?? And, can my MFJ-269 analyzer, help me to?confirm, that the AD9850 is at 7?MHz????Thanks guys,? de Karl, KO8S On Thursday, July 14, 2016 9:22 AM, "bobarr@... [SoftwareControlledHamRadio]" <SoftwareControlledHamRadio@...> wrote:
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Does the display change when you turn the encoder dial? When you PUSH the button does the display change?
If not, it's just a simple hookup error of the encoder leads. (I made it too). Look carefully, experiment. Don't get discouraged, it's a fun project! Remember if you have too much broadcast interference at night you will need a BANDPASS filter. I'm working on mine now. 73 Bo W4GHV since 54 |
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Re: connecting boards.
Does the display change when you turn the encoder dial? When you PUSH the button does the display change?
If not, it's just a simple hookup error of the encoder leads. (I made it too). Look carefully, experiment. Don't get discouraged, it's a fun project! Remember if you have too much broadcast interference at night you will need a BANDPASS filter. I'm working on mine now. 73 Bo W4GHV since 54 |