Russ, if you have rig based CAT controlling the PPT and freq change function, and it appears you do, then you are good to go.? ?

Using a cheap external USB sound card dongle may be better...but...I have never been able to tell a difference between the external sound card dongle and the direct connect between uBITX mic/speaker and the laptop speaker/mic.? But my laptop audio jack broke, so I had to use a external sound card.? Get the $7.99 version if you want to use the external sound card.? Is it better? Beats me.?

You do need some idea of power output, and using the cheapest CB meter will get you started.?



If you hang with any other radio folks, someone will have an old MFJ antenna tuner or SWR/POWER meter that they will pass on to you.? If you find a group of hams, then you will find a group of folks very happy to help you.?

On the topic of tuning your antenna...it is generally a pointless procedure. (Don is ducking now to avoid the flying erasures and tomatoes).? At uBITX power levels, matching the antenna to the uBITX is a fine activity while under CV19 lockdown.? But.? Your antenna and your uBITX will never send a post card saying "thank you", and you will never make a QSO that wouldn't have made without "matching".?

It is good to know you power levels and your SWR. Really good.? But your antenna is what it is, and matching it to your rig makes little difference to the receiving public. And if you jump bands with abandon, then you either "re-match" every time, or you get a automatic antenna tuner with a memory that will snap to your new frequency.? And that complexity will cost you about the same as your uBITX, and produce near zero added value for the uBITX.

Old tube rigs and old timers (said with total respect and humility) have a different view on this. With hundreds or thousands of watts, matching becomes more important. But for us QRP uBITXers, to bother with matching is to stay busy. Not a bad thing at all. And a good learning exercise. But matching will not add any extra FT8 QSOs.

So get a grip on your PWR and your SWR levels, adjust as required, and go fourth into the airwaves. (hahaha...I loved the sound of that!)

Don

Thanks for the replies! It sounds like my first thing to do is to get it up higher. My best option will be from the top of my roof.?

Does anyone have success with putting this an antenna right on or just above a cement tile roof? I think if i pull it tight from the top to my pergola again, it will be touching to several feet above it on the angle to it. If I decide to leave it slack, it would just be resting on it.

I'm guessing it might not be ideal, but a lot better to be up twice as high or so as it is now, even near the roof.
If that doesn't result in some contacts I'll get a swr meter (maybe I'll get one anyway) to check if I need to make any adjustments to this antenna.?

I'm still waiting for an antenna adapter for my V6 but am interested in setting it up for FT8.? So exactly how did you disconnect the PTT connection on the dongle?I'm not sure how the dpdt switch is connected or when you would activate it.? Sorry for being such a dummy.

I didn't do anything special, (maybe I should have?) although maybe this explains why sometimes when I plug in this way from my usb sound card my radio will just start rapidly switching on and off tx, but it doesn't always do this, only sometimes depending on who knows what? haha I'm the dummy not you :)

Hi Group
I have an Ubitx V.5 working well. One problem I found is that when I
connect an USB cable to my Ubitx from the computer for CAT control,
my receive level noise increases substantially. I have an USB cable that
is well shielded for RF and the cable has a ferrite bead on each end. The
Ubitx is well grounded. Maybe I'm expecting too much for a under $200 rig.
You can only ask. Hi Hi.... Any suggestions would be welcomed.
Thanks in advance
Doug WA3ZHG

开云体育

Belthur,

Reading between the lines of your post I will assume that you are operating SSB below 10 MHz, lower sideband (LSB), on a v6 uBiTx.?

The issue that is reported to you is that your output signal is bleeding into the upper sideband (USB).? This can be caused by the BFO not in alignment with the SSB filter.? It can also be caused by overdriving the audio input on the rig.

The procedure that Ashhar Farhan outlines in the video post is the correct one for the alignment of the BFO.? Just be careful to go more towards the 3 KHz red marker than the 500 Hz for the BFO adjustment.? As Reed stated, it will sound a little tinny.

Monitoring your signal is the only way short of a spectrum analyzer (SA) to verify your output signal.?To check your own signal, you might want to find a Web-based SDR? site to monitor for yourself.? There are a number of them around the work listed at

Find one in an area where you have received the bleed issue report if possible, otherwise one that can hear your transmission.

If you do want to go the SA route, I have been having good results recently with an RSP2 SDRPlay.? They no longer make that model, however, the specifications of the RSP1a are better and list price is currently $109 US.? The SA software is free and is now able to do all of the signal purity measurements that the prior releases could not. You will also need a directional tap. I made one from this article:?

And a step attenuator like this one:

So far this is the lowest cost approach that I have found for a SA.? The total cost including all parts, adapters, and cables should be less than $200 US, less if you shop around.? There is a homebrew SA built with parts from eBay that I plan to try.? I do not recommend an RTL-SDR dongle, the RF Explorer, nor the Analog Discover 2.? I have tried all three and they have not produced results that are consistent or require multiple setups to do the harmonic tests.? This is not the case that others have reported, so it may be that I do not have the correct setup for them.

Above are just suggestions, you are responsible for the signal purity of your radios.
73
Evan
AC9TU

There seem to be many Raduino PCB patterns in the files section here.

73,


Mark

Hi Aaron,

I not used MeSquares, but have done quite a bit of "dead bug" construction (which is just placing parts - upside down or not - over an unetched PCB).? Basically I just follow the schematic as it pretty much already organizes the parts in the place you want them on the board.? Start with the receiver antenna connector (or short piece of coax or twisted line) and just start building out.? The receive bandpass filter is first, then the RF amp, mixer, etc all follow.? The build will probably end up long an narrow, but that is good as it keeps the higher level signals away from the lower level ones.? Reading the description of Farhan's build you will see he did it this way too.? You might want to build the VFO, BFO, and AF amp on separate PCB's.? This will allow you to shield the RF one's and also allow you to keep the build from getting too long.? For sure I would put the PA on a separate board.

When soldering parts to the ground plane, remember that is one big piece of copper that you are heating up.? It will take higher heat and a longer heating time than the parts.? Clean then wet the tip of the iron with fresh solder, place the tip on the board where you want to solder, and wait until solder placed on the PCB near the tip will melt by itself.? Then you can place the part to be soldered to it onto the board.? This will keep the part from over heating.

You can place parts upside down or rightside up -- whatever is easiest and makes connections the simplest.

73,


Mark

PS:? Ferrite core toroids or old TV baluns will work much better than tap washers for transformers and inductors as the designer found out in the end.

PSS: If you can't find Toko type transformers for the bandpass filter, you can use fixed inductors and accomplish the filter adjustment by making the capacitors variable instead (trimmer caps).?

Tom -- many uBITXers have faced the same issue...digital modes...long duty cycle...heat...

My approach was to hacksaw larger heatsinks from an old Pentium computer motherboard's CPU.? They have a lot of heatsink!? I then drilled a new hole in about the right position. Screwed the 510 to them and immediately realized that I failed to pay attention in class. If you just screw'em together like I did, they can't touch anything...at all...even air might be a risk...just kidding...? But, if they socially isolate, and ho hand holding, then you can cook'em up.

Better to do as other suggest: Use electrical isolation.?

The good news here...is if you add some mondo head sink, and/or fan...then you can use a old laptop 19v (typical for dells, etc.) powersupply to drive the (red..or...brown?) wire on the little power connector to the mother board that drives the finals (only).? That will feed the 510s with (typically) 19.5 volts, and you will (almost) double your juice out the antenna.? If you have a old 24 volt power supply sitting around...welll...then you will definitely 2x your juice...and make your uBITX a real groovy hot rod. yeeehaaa.

Here are some pics of the salvaged heat sinks next to the originals, and a pic of them installed.? Yes, they practice social isolation. hahah.?

I eventually cut a hole behind the heatsinks and added a fan. I did that after my original IFR510s went all Chernobyl on me under...wait for it...too much heat...hahaha.?

While I am clearly a slow learner, the mighty uBITX has stood up to the abuse.?

I got an email from a trusted friend this morning with some very interesting information for those who have spectrum analyzers that do not have tracking generators, or the new versions of inexpensive VNA's like Ashhar's "Antuino" or the NanoVNA which have sweep functions but I'm not sure exactly how they work in this respect.

Below is a link to a site that explains how to use a reasonably inexpensive wide band noise generator as a substitute for the tracking generator.? Short article that goes into enough detail to help you get started and the second link is to a possible source (eBay - there may be others as well) for the generator itself.? If the links don't work, cut and paste them into your browser's address window.

One possible source of the noise generator:?


This info may help some of you with BFO alignment on your uBITX.

Jim Sheldon, W0EB

I'm still waiting for an antenna adapter for my V6 but am interested in setting it up for FT8.? So exactly how did you disconnect the PTT connection on the dongle?
I'm not sure how the dpdt switch is connected or when you would activate it.? Sorry for being such a dummy.

Russ
K5FJR

I might mention that if you have some old junk PC power supplies, you can salvage these isolation kits from them.? These supplies have several transistors isolated from their heatsinks.? At 3 bucks apiece new, getting these is worth the effort.? You can find junk power supplies at almost any computer repair shop or Habitat Restores and secondhand shops that have old PC's.? I've a good supply of isolation kits from salvage.? Just remember to use some thermal paste.

BruceN / K4TQL
--
"To invent, you need a good imagination and a pile of junk"? -- Thomas Alva Edison (1847-1931)

Hello everyone,
I'm going to start building the??build. It's going to be my first homebrew transceiver project so I will be learning as I go. The instructions say to solder the transistors first but since this is my first go around, I'm not really sure where I should put them on the PCB. I'm going to use Manhattan construction using the QRPme Little MeSquares. So if anyone has any tips or pointers for a newbie, I will be greatly appreciated.??

How has it worked on phone?

As a ham we are required to have control of our signals. Owning a radio is a start but you need to have an idea of it's power output Even a simple CB quality SWR/Power meter can give you an idea.?
--
73
Dave

Gavin,
I also have the same antenna as you do, mine is about 25’ in the air. I‘M making FT8 QSO’S all over NA and the odd EU as well. I also found an antenna tuner works well with this antenna despite what the manufacturer says about matching.
--
?

73
Mick VA3EPM?