Topics

One question only...

Brian L. Davis
 

The bottom line question is simply, is this a legal radio or not!
Yes or No?
Which is it?
I appreciate all the technical and intellectual discourse but the bottom line is, IS IT LEGAL OR NOT?
The average HAM wants to buy the unit and put it on the air.  Can that be done without major modifications?
If it can, then nothing is changed and we go on trying to modify or improve.
If it can't, then we need to abandon the project and move on.
So, which is it?
Can I use this radio or not?

Jerry Gaffke
 

Depends in part on stuff like how much gain the 2n3904's in the 45mhz IF have,
where RV1 is set, how sensitive the mike is.
Those that don't meet spec on some bands and/or modes don't miss it by all that much.
Some users will note that at 5 or 10 watts, it's got weaker obnoxious emissions
than rigs with 100 watts or more that meet spec. 

It should be better.

Jerry


On Sat, Aug 4, 2018 at 09:47 PM, Brian L. Davis wrote:
The bottom line question is simply, is this a legal radio or not!
Yes or No?
Which is it?
I appreciate all the technical and intellectual discourse but the bottom line is, IS IT LEGAL OR NOT?
The average HAM wants to buy the unit and put it on the air.  Can that be done without major modifications?
If it can, then nothing is changed and we go on trying to modify or improve.
If it can't, then we need to abandon the project and move on.
So, which is it?
Can I use this radio or not?

Gordon Gibby <ggibby@...>
 

Brian,  although I might eventually spring for $700 to get a Rigol, until i do, I'm  "quite certain" that the unit(s) I have are quite legal!    And possibly better in some respects than the vacuum tube SB-102 that I'm hoping to bring back on line, and the homebrew linear I built about 50 years ago.


Ashar might have a different issue as a manufacturer but he's a very bright fellow & I'm sure he'll find a few dB here and there if he decides it has to be done.   And we all might slowly make any changes he suggests...


No one who hears my little 5-10 watt signal can figure out exactly what model radio it comes from and I doubt seriously that anyone will be upset by any tiny signals elsewhere.   I have icom's heathkits, and lots of rigs to use.   


Enjoy ham radio, and keep improving yourself and your gear as you go along!!!


Cheers,


gordon 


From: BITX20@groups.io <BITX20@groups.io> on behalf of Jerry Gaffke via Groups.Io <jgaffke@...>
Sent: Sunday, August 5, 2018 1:12 AM
To: BITX20@groups.io
Subject: Re: [BITX20] One question only...
 
Depends in part on stuff like how much gain the 2n3904's in the 45mhz IF have,
where RV1 is set, how sensitive the mike is.
Those that don't meet spec on some bands and/or modes don't miss it by all that much.
Some users will note that at 5 or 10 watts, it's got weaker obnoxious emissions
than rigs with 100 watts or more that meet spec. 

It should be better.

Jerry

On Sat, Aug 4, 2018 at 09:47 PM, Brian L. Davis wrote:
The bottom line question is simply, is this a legal radio or not!
Yes or No?
Which is it?
I appreciate all the technical and intellectual discourse but the bottom line is, IS IT LEGAL OR NOT?
The average HAM wants to buy the unit and put it on the air.  Can that be done without major modifications?
If it can, then nothing is changed and we go on trying to modify or improve.
If it can't, then we need to abandon the project and move on.
So, which is it?
Can I use this radio or not?

Warren Allgyer <allgyer@...>
 

Brian

One condition of your license is it is your responsibility to assure your transmissions meet FCC (assuming you live in the United States) requirements. 

My uBitx does not meet those requirement on most bands and modes below 17 meters. While that does mean yours is the same, it would give a reasonable person reason to expect so. 

In the end it is on you to be sure before you put it on the air. 

WA8TOD

Christopher Miller
 

What I get out of this is sad. I was one of the last hams in the US to actually have to learn Morse code to be able to have HF privileges. 

To me it seems the hobby is so dumbed down that if you expect to buy an unfinished kit and want to treat it like a Kenwood you probably are in over your head.

This from my understanding was grown out of a desire to in fact provide people in places and economic situations to be able to use hf. 

Find a spectrum analyzer or a person who can if you want to build your own rig. 

KF4FTR

Marc Jones
 

I think a lot of you are missing the point with the BITX radios , They are basically a kit radio, And are sold as such , They are for experimentation and hack-ability and as such , Experimentation and Modifications are part of the Bitx Experiance .... They are never going to match any of the major radios by the well known manufacturers ... If people are after such performance then there are plenty of top end radios out there .... I person like the challenge of modding  the little BITX radios ,  For the price of these little Radios you'd be hard pressed to buy a decent  commercial power supply ... Let alone a full HF radio such as the Micro-Bitx , Yes it has issues, Yes it's never going to be a TS-990 or IC-7800 etc.
.... But it's a radio you can get inside, Modify, Tweak, Butcher if need be, All in an attempt to make it more personal to you , And challenging to try to get the best from it ........... It's Fun to use, And cheap as Apple pie .

Regards de

Gw0wvl


On Sun, 5 Aug 2018 at 5:48, Brian L. Davis
<brianldavis@...> wrote:
The bottom line question is simply, is this a legal radio or not!
Yes or No?
Which is it?
I appreciate all the technical and intellectual discourse but the bottom line is, IS IT LEGAL OR NOT?
The average HAM wants to buy the unit and put it on the air.  Can that be done without major modifications?
If it can, then nothing is changed and we go on trying to modify or improve.
If it can't, then we need to abandon the project and move on.
So, which is it?
Can I use this radio or not?

davedt1e@...
 

To the best of my knowledge, the Ubitx is legal if built stock without mods.  In particular ... mods boosting Mic gain on frequencies above 20 meters may cause spurs.  So even with mods, you've still got a legal 20, 40 and 80 meter radio.  Still one heck of a deal for the price.

Jack, W8TEE
 

Christopher:

I kinda agree on one hand, and as much as I hated the code exam (Novice in 1954) and vowed I would never do CW again after I got my General (1955), but something changed after I retired. 1955-2009 was pretty much AM-SSB, but now I find I am really enjoying CW. That Farhan put both modes into the µBITX is one thing that attracted me from the outset, when I bought the BITX-40.

My goal was to provide an inexpensive means by which young hams on a lawn-mowing budget could get on the (HF) air. (Far too many get their Tech, buy an HT for 2M, and shortly thereafter drop out, and I understand that completely.) My first attempt to do something was the Forty-9er (QST, March, 2016). Alas, that was CW only and very few newcomers seem to be interested in CW, and that's a real shame...one step in the dumbed-down process. When I surveyed my club members, 87% said they wanted to learn CW. Yet, when I offered to teach a class, everyone's sock drawer suddenly needed rearranging.

That said, the µBITX still is a great avenue for someone to venture away from VHF/UHF into HF at a very reasonable cost. The stock µBITX is what I call a "semi-kit" and any licensed ham should be able to put a stock version together. Ian and a host of others have collaborated to add a touch-screen (Nextion) display, but still shoehorn it into a Nano. Jim Sheldon and his group have taken it a step further by adding additional features, too. Our JackAl board also extends what the µBITX can do. These extend the capability and functionality of the µBITX and make it a better rig...but you don't have to.

The point is, the µBITX is a great entry-level rig for someone on a limited budget or as a second rig for portable work. However, it is also capable of being a learning device, too. Anyone who reads the posts here and explores ubitx.net is going to be a more effective user of the µBITX. That's a good thing.

At your next club meeting, look around. Mine's getting a little long in the tooth and, frankly, I don't have an effective plan to change that. Clearly, we need young blood in this hobby and, if cost is any barrier to entry, the µBITX can be our ally, provided we "sell it" correctly. It's a semi-kit that almost anyone can put together, use, and learn from, and that should be how we view it.

Jack, W8TEE

On Sunday, August 5, 2018, 3:15:54 AM EDT, Christopher Miller <djmalak2k6@...> wrote:


What I get out of this is sad. I was one of the last hams in the US to actually have to learn Morse code to be able to have HF privileges. 

To me it seems the hobby is so dumbed down that if you expect to buy an unfinished kit and want to treat it like a Kenwood you probably are in over your head.

This from my understanding was grown out of a desire to in fact provide people in places and economic situations to be able to use hf. 

Find a spectrum analyzer or a person who can if you want to build your own rig. 

KF4FTR

Gordon Gibby <ggibby@...>
 

Low pass filters $4.60 ea if necessary ( I have one to use a bitx40 on 80) 


Likely some simple series tuned  filter would add enough additional dB all by itself.  Variable cap, single section , tune most bands with one circuit.    This is ham radio....

Gordon



On Aug 5, 2018, at 09:20, "davedt1e@..." <davedt1e@...> wrote:

To the best of my knowledge, the Ubitx is legal if built stock without mods.  In particular ... mods boosting Mic gain on frequencies above 20 meters may cause spurs.  So even with mods, you've still got a legal 20, 40 and 80 meter radio.  Still one heck of a deal for the price.

ajparent1/KB1GMX <kb1gmx@...>
 

Brian,

There is no FCC approval process for kits and home brew.  It is the Amateur radio operator
to assure its compliance.  

There is enough question as to do all or some not meet the numbers to say the sample size
for those known to have issues is small enough to be an uncertain.

Allison

Lawrence Macionski <am_fm_radio@...>
 

Hi All-
Since very few of us have spectrum analyzers, there are ways to reasonably verify you're transmit signal will slip under the "illegal" problem. My first and last OO notice came in 1966 - I was driving my 6V6 single tube CW transmitter tuned via a #47 pilot lamp and received a notice my 2nd harmonic was being heard 90 miles away. (7154 x 2= 14308) I found tuning my pi-network, I could easily reduce a lot of 2nd harmonics just by backing off a few watts. I wound up homebrewing an antenna tuner and all my problems were gone.. A telephone, a buddy and his receiver 2 miles away confirmed it. An antenna tuner at the transmitter is good for harmonic suppression.

Don't forget that wattmeter.. even with a dummy load will show all kinds of power output - clean or dirty...Remember that Backing down a few watts, will never be heard on the other end of a QSO and can render a cleaner signal. If your going to strive for more power strive for a clean signal as well..

Doug W
 

Since we're on the topic of FCC regulations, while I have never seen an official statistic, I would venture to guess well over 90% of US hams violate 97.313(a) every single time they transmit.


--
www.bitxmap.com

ajparent1/KB1GMX <kb1gmx@...>
 

Lawrence,

Do you have a general coverage receiver?  They work like non-graphic spectrum analyzers
for detecting things.  Its slower and required a lot of manual knob turning.   Of course
one of the radios with a Panoramic display can do that for narrow ranges. 

Allison

ajparent1/KB1GMX <kb1gmx@...>
 

On Sun, Aug 5, 2018 at 07:55 AM, Doug W wrote:
97.313(a)
A KW is the minimum power according to some. ;)

Snark:  For me 100W is serious QRO for HF.  At VHF I'm just warming up the driver.

Allison

Gordon Gibby <ggibby@...>
 

How could we make measurements of signal level accurately? Compared to fundamental?   Note  I would probably be using a 2nd uBitx as the receiver.


Gordon



On Aug 5, 2018, at 11:53, ajparent1/KB1GMX <kb1gmx@...> wrote:

On Sun, Aug 5, 2018 at 07:55 AM, Doug W wrote:
97.313(a)
A KW is the minimum power according to some. ;)

Snark:  For me 100W is serious QRO for HF.  At VHF I'm just warming up the driver.

Allison

Marc Jones
 

Also the cheap SDR dongle with there very wide range , Cobled to HDsdr or similar programmes would suffice for this .

Gw0wvl


On Sun, 5 Aug 2018 at 16:51, ajparent1/KB1GMX
<kb1gmx@...> wrote:
Lawrence,

Do you have a general coverage receiver?  They work like non-graphic spectrum analyzers
for detecting things.  Its slower and required a lot of manual knob turning.   Of course
one of the radios with a Panoramic display can do that for narrow ranges. 

Allison

Kees T
 

I personally don't think there is a problem at all with the existing STOCK uBITX design, or any of the BITX Transceivers, as they have been thoroughly tested by Farhan and others. This is especially the case since they come with the board basically assembled.

If you are concerned and that makes you nervous, I would think someone in your Ham club has access to a Spectrum Analyzer and knows how to use it.  If you just want to be safe, just add a switchable Low Pass Filter (LPF) to the 5-10W output for the frequencies you are going to use.....can't hurt, unless you forget to switch it to the correct band. W8DIZ used to offer a kit and I'm sure there are others out there now.

.....Now for those of you who are trying squeeze more power out of the stock RF PA unit through "various means".....you are on your own to control emissions.

73 Kees K5BCQ

Arv Evans
 

Brian

The answer may be "maybe".  Original design provides limited SSB levels due to the
fixed gain microphone amplifier and a standard microphone.  Using an antenna tuner
between uBITX and antenna helps to lower the level of any harmonics or spurious
outputs.  Given that, we then have to rely on the measurement gurus with their
extensive test equipment to tell us if it meets US FCC specifications.  Unfortunately
this will be difficult because they are busy working on modified uBITX systems and
not on basic out-of-the-box boards. 

Arv
_._


On Sat, Aug 4, 2018 at 10:48 PM Brian L. Davis <brianldavis@...> wrote:
The bottom line question is simply, is this a legal radio or not!
Yes or No?
Which is it?
I appreciate all the technical and intellectual discourse but the bottom line is, IS IT LEGAL OR NOT?
The average HAM wants to buy the unit and put it on the air.  Can that be done without major modifications?
If it can, then nothing is changed and we go on trying to modify or improve.
If it can't, then we need to abandon the project and move on.
So, which is it?
Can I use this radio or not?

ajparent1/KB1GMX <kb1gmx@...>
 

Using a ubitx as a receiver is harder as you have no metering.  Hard to compare values!
Also using a radio with spurs to test one for spurs makes for added difficulty.

One possible is an all band radio doesn't have to be great or especially
selective or sensitive.  In my earlier days a Hallicrafters S38 was a real
handy item, not much of a radio but it could detect RF.

Solution is to use a DVB-t stick that covers HF, or used a computer with sound card
and tap in to the product detector output and run spectran or similar (fldigi) to get
a quantifiable measurement.  The other thing needed is attenuators both those
that can stand 10-15W (home brew works at HF) and step attenuators once
the power is below a few milliwatts.

If that sounds too complex then learning or club activity around how to do this
is in order.

I can make suggestions but all answers, all the time.  Sorry, I'm doing the
learning part too as its one of the challenges I enjoy.  I didn't always have all
the gear, I still learned the theory and made the measurements.

Allison

Arv Evans
 

One of the reasons for providing ham gear in kit form is that owner/operator built units
are subject to different requirements than commercially built equipment.  All BITX
designs to-date have been marketed as partial or total kits-of-parts to keep them inside
the owner-built realm.  Being owner-built it is that owner's responsibility to insure
compliance with applicable rules.  This helps to keep prices down and does require that
the builder have the technical skills he/she claimed to have during their license exam. 

Arv
_._


On Sun, Aug 5, 2018 at 1:15 AM Christopher Miller <djmalak2k6@...> wrote:
What I get out of this is sad. I was one of the last hams in the US to actually have to learn Morse code to be able to have HF privileges. 

To me it seems the hobby is so dumbed down that if you expect to buy an unfinished kit and want to treat it like a Kenwood you probably are in over your head.

This from my understanding was grown out of a desire to in fact provide people in places and economic situations to be able to use hf. 

Find a spectrum analyzer or a person who can if you want to build your own rig. 

KF4FTR