ok I have built my radio kit and the dds vfo and when I power it up everything looks good.? I can get the display to change the frequency and when I key it make a nice sound a bit loud but nice sound.? problem is I am not getting any signal into or out of radio.? I took it to one of my elmers just to check the output frequency and there was none and no signal was herd.? I have been back through board and looked for solder bridges and check the correct orentiation of the diodes and Capacitors and also looked for cold solder joints.? I am not seeing anything that looks to be wrong. I did have the filter that we had to make up for the receive in opposite from the picture but I have fixed that and still nothing.? any help would be appereciated.?? Thanks?? Nathan?? K7NDM
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There seems to be problems with the encoder switch connection. I am puzzled by this because the schematic clearly shows the encoder connected to D4 on the Nano. The problem is that people don't seem to understand that D4 IS pin 7 on the Nano. Look closely at the schematic from Farrukh web site at the file labeled:
dds-vfo-assembly-manual-rev2.pdf
If you have not downloaded the assembly manual and code from his site:
?
you should do so before building the Forty-9er.
73, Jack, W8TEE ??
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Re: Power supply for the transceiver
So I decided to check the actual current draw to be sure I had a decent choice. ?I prepared a 50 ohm resistive load for the antenna, plugged in my ear buds and set the supply voltage to 12.0 volts with my bench supply. ?I put my Harbor Freight ?vom in as an ammeter and observed the current to be .14 amps on receive and .54 amps during transmit.?
Noticing that my fat fingers had put in .3 amps when the math really was .39 amps (I had intended to round it to 400 ma and didn't notice the typo), and that I thought that would be safe, I needed to correct that. ?My actual draw was bigger and probably since different parts of the circuit are involved and there must be efficiency stuff to consider, I should have expected something higher. ?.54 amps is higher but not as high as was obtained with the 13,85 volts and below the specified limit of 750 ma on the cord.
I think the cheap cable sold on eBay is not a bad choice. ?I am waiting for it's delivery so I can see the actual voltage but it lets me use a bunch of battery backups that I have for phones, etc ?and they can be charged from the usb outlet on my car, my generator,my charging station, etc. It may be a better idea to use higher voltage for the power but it is not a bad choice for emergency use.??My thermoelectric stove lamp can run the transceiver so I can run my system if I just have firewood. ?Not bad but probably a bit extreme for an idea.
WB6TOU
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It worked beautifully.? Thanks.?? However to get rotary push switch to work, had to change from pin7 to pin 4.... Now everything works.? Tnx agn...? KJ4ZI
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Re: Implementation of the voltmeter option
I asked the same question when I was coding the warning system. As always in amateur radio, it depends. ? My SLA batteries fully charged give me 12.7v. Setting the lower limits to 11.7 and 11.5 would probably work. Tweak the upper limits to 12.8 and 13.0 ? However if you want to run it with a conventional power supply of 13.8v then the upper limit numbers mentioned above would not work. Here 13.9 and 14.0 is not out of reason. ? In the end I just pulled numbers out of my aft end and let the end user decide what limits are appropriate for his rig, situation, and usage. ? Till later Hank K5HDE
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Re: Implementation of the voltmeter option
My thought is that 13.5VDC is perfect for 2-3w output Brian. And to go easy on Q5, What is the output at 13.5V? And did yo use a heat sink??
Although the D882 transistor could be pushed further in PCM and proper cooling, 3w is adequate, QRP I Just drive up Mt Washington, connect?a piece of copper wire with a micro-tuner ?... ? ;)
Anyway, yes, power increases with Vsup but you must keep the output swing within rated maximum to avoid distortion. The D882's absolute max rating is 30V Vceo . Q5 wants to double Vsup,?so some margin helps keep the output in the linear region albeit class C. ? ?..jim-ab1br ?
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Re: Power supply for the transceiver
Add-addendum: ...of course the DDS takes its share of power too...
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Re: Power supply for the transceiver
Addendum: the 49er RCVR draws ~115mA, so minus the total Xmit current would be? 860mA - 115mA or ...? ?;)
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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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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
--
Lee Hiers, AA4GA
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The 49¨¨r is a nice, pretty sensitive, transciever. I love that it can "detect" the SSB stations also. But in the CW band you hear the same station on both sides of the zero point. Which side do you have to tune to, to get the right transmit freqency? 73 de OZ1QZ / John
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I have an article in QRP Quarterly about varying the tuning rate according to how fast you are turning the encoder. I have mine defaulted to 100Hz but when you turn it fast, the rate is 5 KHz. Give it a try.
Jack, W8,TEE |
From:
ab1br@... [SoftwareControlledHamRadio] ;
To:
;
Subject:
[SoftwareControlledHamRadio] Re: connecting boards.
Sent:
Fri, Jul 15, 2016 2:54:54 PM
?
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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Wrong library. Go to yourduino.com,look at their I2C displays and download that library
Jack, W8TEE |
From:
ab1br@... [SoftwareControlledHamRadio] ;
To:
<SoftwareControlledHamRadio@...>;
Subject:
[SoftwareControlledHamRadio] Re: Software Upgrade
Sent:
Fri, Jul 15, 2016 8:40:32 PM
?
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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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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Question of transmit freqency
The 49¨¨r is a nice, pretty sensitive, transciever. I love that it can "detect" the SSB stations also. But in the CW band you hear the same station on both sides of the zero point. Which side do you have to tune to, to get the right transmit freqency? 73 de OZ1QZ / John
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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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jjpurdum
Lee Hiers