¿ªÔÆÌåÓý

  1. BITX20
  2. Messages
Expanded Topics Messages Polls
Date
Re: Spurs and Harmonics - Definitions and Measurements

Gordon Gibby
 

¿ªÔÆÌåÓý

Everyone has a right to their opinions, but you can¡¯t order manufacturers around. If there are customers who value their products, manufacturers will sell them.

If you want strongly to have more filtering, this is a perfect opportunity for you to start doing what you feel the manufacturer has left incomplete. ?This is ham radio! ? ?This is not CB. ?This is not family radio service. ?

You can build it yourself, or you can go into business and manufacture it for others and try to make a profit! ?(Good luck.)

Here is a webpage that gives some design information for band pass filters

I¡¯m sure there are many others. ??

If you just want more low pass filtering, add in external relays and toss in one extra section on the low pass filter. ? The Gerber files for the external relay system that I built are free. ?Send them to china with $25 and you¡¯ll have five or 10 boards to experiment with!?


When I was a novice ?40 years ago, heathkit ?sent me a COMPLETELY ?unassembled radio! ? You had to Solder & place ?every single part of it together and then you worked and worked to fix your goofs and make the thing work. ? They bitx products are already assembled and we have tons of documentation of their characteristics. ? You are free to improve on them! ? Again, this is him radio. This is not CB. This is not family radio service.

Pick up a soldering iron and get to work!


Cheers

Gordon


On Mar 11, 2019, at 15:46, Ashhar Farhan <farhanbox@...> wrote:

I see no reason why we should not be compliant. It is just that we are trying to be cost effective in doing so.

- f

On Tue 12 Mar, 2019, 12:22 AM Jerry Gaffke via Groups.Io, <jgaffke=[email protected]> wrote:
The regs changed, and old gear is grandfathered in.
The uBitx is new gear, should meet the -43dBc spec here in the USA.
Simple as that.

> What I did find was a procedure written by the IEEE which gave step by step how to test for the spurious emissions.??

Part 97 applies specifically to Amateur Radio, and specs -43dBc.? Search for "97.307" within this document:
? ??

Part 15 deals with RFI from non-licensed devices, and is a whole other kettle of fish.
? ??
Since such devices do not necessarily radiate on purpose, there may be no carrier to compare the emission with.
So the regs are written much differently.

Generally speaking, regs for Amateur Radio seem fairly lax.
Especially that grandfather thing.

And generally speaking, these particular regs seem pretty simple and self consistent.
Government regs can get a whole whole lot worse.? ?;-)

Jerry, KE7ER


On Mon, Mar 11, 2019 at 09:51 AM, BruceN wrote:
Thanks Mark, Ashar and Curt.

Mark I did look but I didn't figure it would be in Part 97.? What I did find was a procedure written by the IEEE which gave step by step how to test for the spurious emissions.? But, if you look closely at what is written in what you highlighted, the emitted spurious power for a low power rig can be interpreted to be far lower than for a higher power transmitter.? In the second part, those dealing with transmitter installed before 2005, achieving this goal with a high power transmitter might be excrutiatingly difficult but may be easy to achieve with a low power transmitter.? In the first part, they are specifying according to suppression.? In the second part, they list the actual emitted power permitted.? Things are not equal.? It would be better is everyone measured using the same units.

And, yes, it can be such gibber when even the regulations don't seem to agree within the same paragraph.? I do realize they are addressing two different vintages but they are using two different measuring systems.

My additional nickel.

Bruce, K4TQL
Re: Spurs and Harmonics - Definitions and Measurements

 

I see no reason why we should not be compliant. It is just that we are trying to be cost effective in doing so.

- f

On Tue 12 Mar, 2019, 12:22 AM Jerry Gaffke via Groups.Io, <jgaffke=[email protected]> wrote:
The regs changed, and old gear is grandfathered in.
The uBitx is new gear, should meet the -43dBc spec here in the USA.
Simple as that.

> What I did find was a procedure written by the IEEE which gave step by step how to test for the spurious emissions.??

Part 97 applies specifically to Amateur Radio, and specs -43dBc.? Search for "97.307" within this document:
? ??

Part 15 deals with RFI from non-licensed devices, and is a whole other kettle of fish.
? ??
Since such devices do not necessarily radiate on purpose, there may be no carrier to compare the emission with.
So the regs are written much differently.

Generally speaking, regs for Amateur Radio seem fairly lax.
Especially that grandfather thing.

And generally speaking, these particular regs seem pretty simple and self consistent.
Government regs can get a whole whole lot worse.? ?;-)

Jerry, KE7ER


On Mon, Mar 11, 2019 at 09:51 AM, BruceN wrote:
Thanks Mark, Ashar and Curt.

Mark I did look but I didn't figure it would be in Part 97.? What I did find was a procedure written by the IEEE which gave step by step how to test for the spurious emissions.? But, if you look closely at what is written in what you highlighted, the emitted spurious power for a low power rig can be interpreted to be far lower than for a higher power transmitter.? In the second part, those dealing with transmitter installed before 2005, achieving this goal with a high power transmitter might be excrutiatingly difficult but may be easy to achieve with a low power transmitter.? In the first part, they are specifying according to suppression.? In the second part, they list the actual emitted power permitted.? Things are not equal.? It would be better is everyone measured using the same units.

And, yes, it can be such gibber when even the regulations don't seem to agree within the same paragraph.? I do realize they are addressing two different vintages but they are using two different measuring systems.

My additional nickel.

Bruce, K4TQL
Re: AGC Pre-Oders are in and built!

 

making the last 6 and will have 26 more posted.
--
David

?N8DAH
Re: AGC Pre-Oders are in and built!

Gordon Gibby
 

¿ªÔÆÌåÓý

As soon as I get back in stock I¡¯m going to purchase two. Been very busy lately couldn¡¯t get to the stuff


On Mar 11, 2019, at 14:16, N8DAH <Dherron@...> wrote:

I have a few years left in me, my hands are slowly rebelling and going weak. I may be steady but my grip is going.
--
David

?N8DAH
Re: LPF kit for ubitx v3

Brian L. Davis
 

Text refers to CLK#0 but picture is CLK#2.
Which one?
Re: Spurs and Harmonics - Definitions and Measurements

 

The regs changed, and old gear is grandfathered in.
The uBitx is new gear, should meet the -43dBc spec here in the USA.
Simple as that.

> What I did find was a procedure written by the IEEE which gave step by step how to test for the spurious emissions.??

Part 97 applies specifically to Amateur Radio, and specs -43dBc.? Search for "97.307" within this document:
? ??

Part 15 deals with RFI from non-licensed devices, and is a whole other kettle of fish.
? ??
Since such devices do not necessarily radiate on purpose, there may be no carrier to compare the emission with.
So the regs are written much differently.

Generally speaking, regs for Amateur Radio seem fairly lax.
Especially that grandfather thing.

And generally speaking, these particular regs seem pretty simple and self consistent.
Government regs can get a whole whole lot worse.? ?;-)

Jerry, KE7ER


On Mon, Mar 11, 2019 at 09:51 AM, BruceN wrote:
Thanks Mark, Ashar and Curt.

Mark I did look but I didn't figure it would be in Part 97.? What I did find was a procedure written by the IEEE which gave step by step how to test for the spurious emissions.? But, if you look closely at what is written in what you highlighted, the emitted spurious power for a low power rig can be interpreted to be far lower than for a higher power transmitter.? In the second part, those dealing with transmitter installed before 2005, achieving this goal with a high power transmitter might be excrutiatingly difficult but may be easy to achieve with a low power transmitter.? In the first part, they are specifying according to suppression.? In the second part, they list the actual emitted power permitted.? Things are not equal.? It would be better is everyone measured using the same units.

And, yes, it can be such gibber when even the regulations don't seem to agree within the same paragraph.? I do realize they are addressing two different vintages but they are using two different measuring systems.

My additional nickel.

Bruce, K4TQL
Re: Spurs and Harmonics - Definitions and Measurements

 

Lots and lots of these rigs are going into dipoles with no tuner.
That will radiate just fine on the third harmonic, and the pattern
may well be such that your FCC monitor is sitting in a third harmonic lobe.

In the general case, can't count on the antenna system to to make the uBitx legal.
The uBitx really should be clean out of the box.

Jerry, KE7ER



On Mon, Mar 11, 2019 at 11:18 AM, Arv Evans wrote:
Bruce, K4TQL
?
Small point...the FCC monitors would be testing received RF.? This may be via a remote monitoring
station or from a van parked down the street from your house.? This means that the full system,
including ATU and antenna will be present in signal analysis.? Most discussions fail to include
filtering effects of these components that are external to your transceiver (some designs are better
than others).? This lends credibility to having another ham who is some distance from your location
perform tests to see how pure your signal might be. ?
?
Testing in an anechoic chamber is the way equipment is tested for type approval or in case of
legal proceedings.?
?
Arv? K7HKL
Re: Spurs and Harmonics - Definitions and Measurements

Laurence Oberman
 

While we should and most of us are trying to comply, we have some
benefits on our side that will lessen the concern here.
Speaking for the USA anyway.

1. Its not a commercial radio with FCC approval, its a kit and we do
have the ARRL always encouraging homebrew and
lots of efforts to correct the issue by all of us acts to our benefit
2. If you go by usual QRP power of 5 watts then both my v4 radios
should be within SPEC. The heating issue Allison
described will be harder to make happen on lower power as well as my V5
3. Most QRP activity at 5 watts is digital or CW and in any case SSB
will be even lower on average power
4. So if limited to 5 watts I think we would be OK

I will reduce the power this coming weekend using RV1 and re-run all the tests

The FT817 only has 5W

I figured why not toss my penny in too.
73
Laurence Oberman
KB1HKO

On Mon, Mar 11, 2019 at 2:18 PM Arv Evans <arvid.evans@...> wrote:

Bruce, K4TQL

Small point...the FCC monitors would be testing received RF. This may be via a remote monitoring
station or from a van parked down the street from your house. This means that the full system,
including ATU and antenna will be present in signal analysis. Most discussions fail to include
filtering effects of these components that are external to your transceiver (some designs are better
than others). This lends credibility to having another ham who is some distance from your location
perform tests to see how pure your signal might be.

Testing in an anechoic chamber is the way equipment is tested for type approval or in case of
legal proceedings.

Arv K7HKL
_._



On Mon, Mar 11, 2019 at 7:44 AM BruceN <k4tql@...> wrote:

I've seen many messages relating to the cures for spurs and harmonics for the V3, V4 and V5 units. Right now there are nearly 1000 messages dealing with this topic. But, I'm confused. And, what exactly are the limits for emission of spurs and harmonics? I've researched the FCC regs and it's like reading a foreign language to me. But what I did glean is that the FCC tests in, basically, an anechoic (to RF) chamber and report the results, depending on frequency range, in microvolts.

What I see in the messages is that folks are reporting spur and harmonic levels in dB. Now, db is a ratio so what are those db values compared to? To the level of the primary signal? Are they measuring spur and harmonic suppression? Again, compared to what?

If spurs and harmonics readings are to be given as a particular level, they should be reported as dBm, not dB. dBm is also a ratio but it is compared to a fixed level of 1 milliwatt. The emitted power given in those units would be the same if measured on a transmitter running 10 watts as a transmitter running 100 watts.

However, if the readings are given in dB, it is representing suppression. A -50 dB reading on a 10 watt transmitter will have an actual radiated power far less than a -50 dB reading on a 100 watt transmitter. So, if we're measuring and reporting dB on the uBitx, maybe those reported levels are not so bad as folks think. The radiated power level would be far less than other signals out there. Easily seen on a scope with high gain but maybe not readable a mile away or even 3 feet away.

If you are measuring actual output power of the spurs and harmonics, report your readings in dBm. And if that is the units being used, the uBitx might need some help.

So which is it?

My nickel (2 cents inflated).

Bruce, K4TQL
Re: ubitx v4 - distortion in received audio

 

I thought the uBITX audio volume was low, until my kids told me to change the battery in my hearing aid.? 8-)
_._


On Mon, Mar 11, 2019 at 9:43 AM Ramakrishnan Muthukrishnan <ram@...> wrote:
On Mon, Mar 11, 2019, at 6:57 PM, Mark - N7EKU wrote:
Hi Ramakrishnan,

Not sure if your audio problem is related to the audio amp section, but if it is this link shows a fix that shouldn't be too hard to do:


Make sure you read Allison's post number 53356 in that link for adjusting the operating point of Q71.

Thanks so much Mark. I also spoke to Raj. I will try the modification tomorrow and report back.

73
Ramakrishnan VU3RDD
Re: Spurs and Harmonics - Definitions and Measurements

 

Bruce, K4TQL

Small point...the FCC monitors would be testing received RF.? This may be via a remote monitoring
station or from a van parked down the street from your house.? This means that the full system,
including ATU and antenna will be present in signal analysis.? Most discussions fail to include
filtering effects of these components that are external to your transceiver (some designs are better
than others).? This lends credibility to having another ham who is some distance from your location
perform tests to see how pure your signal might be. ?

Testing in an anechoic chamber is the way equipment is tested for type approval or in case of
legal proceedings.?

Arv? K7HKL
_._



On Mon, Mar 11, 2019 at 7:44 AM BruceN <k4tql@...> wrote:
I've seen many messages relating to the cures for spurs and harmonics for the V3, V4 and V5 units.? Right now there are nearly 1000 messages dealing with this topic.? But, I'm confused.? And, what exactly are the limits for emission of spurs and harmonics?? I've researched the FCC regs and it's like reading a foreign language to me.? But what I did glean is that the FCC tests in, basically, an anechoic (to RF) chamber and report the results, depending on frequency range, in microvolts.

What I see in the messages is that folks are reporting spur and harmonic levels in dB.? Now, db is a ratio so what are those db values compared to?? To the level of the primary signal?? Are they measuring spur and harmonic suppression?? Again, compared to what??

If spurs and harmonics readings are to be given as a particular level, they should be reported as dBm, not dB.? dBm is also a ratio but it is compared to a fixed level of 1 milliwatt.? The emitted power given in those units would be the same if measured on a transmitter running 10 watts as a transmitter running 100 watts.

However, if the readings are given in dB, it is representing suppression.? A -50 dB reading on a 10 watt transmitter will have an actual radiated power far less than a -50 dB reading on a 100 watt transmitter.? So, if we're measuring and reporting dB on the uBitx, maybe those reported levels are not so bad as folks think.? The radiated power level would be far less than other signals out there.? Easily seen on a scope with high gain but maybe not readable a mile away or even 3 feet away.

If you are measuring actual output power of the spurs and harmonics, report your readings in dBm.? And if that is the units being used, the uBitx might need some help.

So which is it?

My nickel (2 cents inflated).

Bruce, K4TQL

Re: AGC Pre-Oders are in and built!

 

I have a few years left in me, my hands are slowly rebelling and going weak. I may be steady but my grip is going.
--
David

?N8DAH
Re: Should I wait to buy a ubitx?

Vince Vielhaber
 

If it bothers you so much, I think you, yourself, should suspend buying one and go buy a Yeasu or Kenwood or Icom or maybe even a Baofeng!

Vince - K8ZW.

On 03/11/2019 01:21 PM, Bill Harris - K5MIL wrote:
I think they should suspend sales until they can finally get it right
and produce a unit that you don't have to mod to high heaven to make it
work properly.

Bill - K5MIL
--
K8ZW

Re: AGC Pre-Oders are in and built!

 

Amazing! I imagine you do brain surgery on the weekends (grin) Steady hand. I used to be able to do smd however now I would probably sneeze and blow the whole pile of boards and parts bin right off the table!?
Very nice work!
Jim
Re: #bitx20 Ver 5 relays. #bitx20

 

I have Axicom relays installed because it was ver. 3 and it was really needed. Ver. 5 is greatly improved and, according to the advertising, should be fine. If you replace them with Axicom you should not go any wrong. But if you feel confident to remove them. I found it difficult, honestly. Another ham said it would have been easy if I had used a wet wood toothpick to remove the excess of solder in the holes.


Il 11/mar/2019 18:08, <Jscook@...> ha scritto:
Just received what I assume is a Ver 5 mother board , shows 06 19 stenciled on board, and it has HFD27/012-S relays. Should these be changed to axicom relays?
Jim


Re: ubitx.net up to date

 

Thank you, Curt!? ?It's actually a very nice construction document.? Based on that, it wouldn't be too hard to make into a kit.


On Mon, Mar 11, 2019 at 09:03 AM, Curt wrote:
https://qsl.net/nf4rc/2018/OutboardRelaysDesignDocumentTry3.pdf
Re: Should I wait to buy a ubitx?

 

I think they should suspend sales until they can finally get it right and produce a unit that you don't have to mod to high heaven to make it work properly.?

Bill - K5MIL
#bitx20 Ver 5 relays. #bitx20

 

Just received what I assume is a Ver 5 mother board , shows 06 19 stenciled on board, and it has HFD27/012-S relays. Should these be changed to axicom relays?
Jim
Re: Ordered my v5 ubitx today, case delivery tomorrow!

 

I was shocked at the speed the case was delivered . Ordered it Thursday and it arrived today.? ?That's as fast as Amazon and it came from India!
Re: AGC Pre-Oders are in and built!

SAM R BURNES
 

¿ªÔÆÌåÓý

Oh my goodness!


On Mar 11, 2019, at 11:49 AM, N8DAH <Dherron@...> wrote:

Thought I would post a live stream building the next batch enjoy


--
David

?N8DAH
Re: Spurs and Harmonics - Definitions and Measurements

 

Thanks Mark, Ashar and Curt.

Mark I did look but I didn't figure it would be in Part 97.? What I did find was a procedure written by the IEEE which gave step by step how to test for the spurious emissions.? But, if you look closely at what is written in what you highlighted, the emitted spurious power for a low power rig can be interpreted to be far lower than for a higher power transmitter.? In the second part, those dealing with transmitter installed before 2005, achieving this goal with a high power transmitter might be excrutiatingly difficult but may be easy to achieve with a low power transmitter.? In the first part, they are specifying according to suppression.? In the second part, they list the actual emitted power permitted.? Things are not equal.? It would be better is everyone measured using the same units.

And, yes, it can be such gibber when even the regulations don't seem to agree within the same paragraph.? I do realize they are addressing two different vintages but they are using two different measuring systems.

My additional nickel.

Bruce, K4TQL
50421 - 50440 of 116201