Date   
Re: uBitx Unfiltered

ajparent1/kb1gmx
 

Jerry,

I also said that.  However it was assumed the 20M LPF worked as we found
out later it does not.

The big LPF (9 element at T1) however has a corner frequency of about
33mhz (33.68 mhz in mine) and that is the 3db point so below that its an
open pipe.

Rather than hash minor points the issue is below 20mhz the output filters
do not work as designed.  Warren showed a lot of work to prove that.   
Above 20mhz there is no filtering.  Spurs below  the cutoff for the 10M
output LPF and the other 33mhz filter have a unfiltered path.

Now we add to that high power output on the lower bands tends to couple
into the IF especially the 45mhz IF and contribute new tones to the mix
increasing the products at the output.  Several of us have seen that but 
it was not understood why.   Best example is 80M SSB at 10W or more,
Not only does one see harmonics leaking by the filter but there are a
host of other seemingly random products that are the result of the output
signal and harmonics plus 45mhz and OSC2.  Push just a little for say
15 to 20W and those grow alarmingly.

Allison

Re: Personal Best Distance, SSB Phone #ubitx

Don, ND6T
 

First SSB contact with new uBITX was with JE6EHP on 20m with an end-fed random wire. Nice long chat. Well over 8,000 Km. -Don

Re: ATU for mBITX

Bob KB1TEK
 

The Elecraft T1 seems pretty ideal, but I've never used it.  Does anyone else have experience with that tuner?

Re: UBITX V3 TX GAIN VARIATIONS

Kees T
 

On Tue, Aug 28, 2018 at 04:25 PM, Rod Davis wrote:
WARNING: q911,q912,q92,q93,q96,q97 all dissipate at least 296 mW. That
means 250 mW transistors are not acceptable.

So, in searching for a better Ft device for the TX chain:
the BFR106 has the dissipation, but the 3.5 to 5GHz Ft invites instability
the MMBT10     lists dissipation at 225 mW, so it may not be a good candidate
the MMBT2369 lists dissipation at 225 mW, so it may not be a good candidate
the DTX2222A has the dissipation, but the Ft is not better than 2n3904, and
the footprint is not compatible with the board.
I was wondering about the reasoning behind using several parallel 2N3904 transistors in the uBITX circuit.....they are inexpensive, but why not just use a single 2N2222 ?

73 Kees K5BCQ

Re: uBitx Unfiltered

ajparent1/kb1gmx
 

Lower the gain of the two TX IF amps to 11db each.
There is excess gain.

Less pad and less gain.  Why? the higher gain picks up stuff out of band
and adds it to the mix, result is more and greater spurs.  The pad lowers
the carrier to signal as the carrier is leakage around the balanced
mod and filter.

The problem with padding the 45mhz filter was I tried it and no useful effect.
Lowering the gain was more productive and adding a filter to the 45mhz output 
helped as well.  Reason is the 45mhz amp picked up stuff from the power amp
and adds it to the output creating a greater number of products related to
harmonics of the lower bands and the unfiltered products of the higher bands.
The biggest reason is coupling through power leads and current loops in the
ground plane.

Short explanation is too much stuff getting into places it should not be creating
more new stuff.

Simple fixes like changing a resistor or pad does not fix that.

Allison

Re: Can we start using SUBGROUPS? uBiTX, biTX40, QRPKITS, Original BiTX20, Homebrew, Other?

Doug W
 

On Thu, Aug 30, 2018 at 08:43 AM, Chuck WB6GPO wrote:
How about adopting an informal convention of putting a TOPIC PREFIX on the thread title?
Like the already available hashtags that almost never get used?  It is a very good idea.  It just gets lost in the implementation.
 
--
www.bitxmap.com

Re: Personal Best Distance, SSB Phone #ubitx

iz oos
 

New Zealand, ssb 3w qrp with the Spanish ILER20. I logged that as an ordinary qso. I was not in the States of course... But in Italy. New Zealand is exactly on the other side of planet earth from my qth. Just let me say that if you hear anything around s9 or more if you use a qrp you can have a qso, of course it will be more difficult during a pile up. So give up FT8 and come back to cw-ssb!


Il 30/ago/2018 16:28, "EI_Frank" <mckeownfg@...> ha scritto:
So what's your personal best distance on SSB Phone.
I'll kick off with a meagre 380 km's (236 miles). With an End Fed half wave wire on 40m with a uBitx.
Who's next. ?


Re: Personal Best Distance, SSB Phone #ubitx

ajparent1/kb1gmx
 

On 6M K9ppy and W4IMD using HB portable rig at 820mW. into the
4 element beam at 33ft.  

For HF:
For 5W using my Argonaut 505 on 40m the best was SV54rwu from W1 country.
For the Slopbucket 20, DL5ARH
These two using LNR EF-quad at 30ft.

For the KNQ7A (40M) VK3 foundation station while mobile (8ft centerloaded whip).
That radio does about 7-8W  at 13.8V.

For 10m during the last solar minimum all of South America, the carib islands,
Falklands and Antartica all using 4W SSB HB into one of two antennas the
PAR EF40/20/10  and the K6STI 10M loop with the top 20ft up.  That was
over a 5 month period.   I credit the K6STI 10M loop a 73" wide by 146" high
rectangle for the better part of all that as it was aimed to favor South America.
The par EF40/20/10 as set up then favored east west paths.

Antennas that are oriented in the desired direction and high enough to
be effective seem to make a difference.

Allison

Any Gerber Experts Round Here? #kicad #ubitx

Ben Holmes
 

I'm trying to use the free trial of Gerbview to convert an RS-274D Gerber file to an RS-274X... but I'm a tad lost in the details of doing so - as I'm not experienced at this. I've already paid for a board at a Chinese firm, and even though the money is already spent, I'm currently not getting anything for it!

Anyone here willing to help? Or point me to where I can get some help? (And while free is great, I'm not unwilling to pay...)

73 Ben Holmes, K6QV

Re: uBitx Unfiltered

Kees T
 

Allison,

I think I said overdriving the mixers is the problem in one of the notes. So how would you go about reducing those drive levels ? Reduce the signal level or increase the LO level.

The 4 dB pad on the input to the 12MHz crystal could be increased, The 6dB pad on the LO's could be reduced to something less. You could add a pad to the 45MHz Mixer input. I don't know if you want to do anything with the last mixer.

In the interests of efficiently using existing parts, how about swapping the 4dB pad (input to the 12MHz section) with the 6dB pad parts on that mixer LO ?

73 Kees K5BCQ

Re: personal distance record with FT8 #ft8 #ubitx

Doug W
 

On Thu, Aug 30, 2018 at 09:31 AM, Gordon Gibby wrote:
Yes, but their  throughput is very low, and in emergencies, I’m not sure how much vital messaging you can get done with them.....
 
Communications protocols are a trade off
 
 
Gordon
 
Horses for courses.  My wire antenna would make a horrible climbing rope.  Assuming your emergency set up covers multiple bands and includes digital modes I would think getting a quick low power look at propagation would be useful.  That aside, you might be interested in FT8call.  I don't know much about it other than what I've read but it might be useful for your needs https://github.com/jsherer/ft8call
 
--
www.bitxmap.com

Re: ATU for mBITX

R. E. Klaus
 

My opinion only, others will have their own. A remote tuner at the antenna is the best choice as it will have the least loss in your coax. as for automatic vs manual, it is mostly personal taste. In some cases a manual tuner may give a better match than an auto tuner but the auto tuner will work well 99.7% of the time.

Re: personal distance record with FT8 #ft8 #ubitx

Gordon Gibby <ggibby@...>
 

Yes, but their  throughput is very low, and in emergencies, I’m not sure how much vital messaging you can get done with them.....

Communications protocols are a trade off


Gordon




On Aug 30, 2018, at 10:19, Doug W <dougwilner@...> wrote:

The K1JT modes sure do give you a high action to watt ratio.  I have FT8 QSO's between USA and ZL on just over 4w which is 13,176.51km (8,235.318 miles). On my raspberry pi WSPR rig I have reports from ZL as well and that is on .1w.
--
www.bitxmap.com

Personal Best Distance, SSB Phone #ubitx

EI_Frank
 

So what's your personal best distance on SSB Phone.
I'll kick off with a meagre 380 km's (236 miles). With an End Fed half wave wire on 40m with a uBitx.
Who's next. ?

Re: personal distance record with FT8 #ft8 #ubitx

Doug W
 

The K1JT modes sure do give you a high action to watt ratio.  I have FT8 QSO's between USA and ZL on just over 4w which is 13,176.51km (8,235.318 miles). On my raspberry pi WSPR rig I have reports from ZL as well and that is on .1w.
--
www.bitxmap.com

Re: Nextion 3.2 for CEC 1.097 #ubitx

SV9CVJ Nikos
 

HI John

I've done all the resizing except page 11 and 0 px which is a little complicated for me .

Nikos SV9CVJ

Re: Can we start using SUBGROUPS? uBiTX, biTX40, QRPKITS, Original BiTX20, Homebrew, Other?

Chuck WB6GPO
 

How about adopting an informal convention of putting a TOPIC PREFIX on the thread title?  For example:

uBitx: How do I connect the Raduino to the main board?

Common prefixes could include:

uBitx:
bitx40:
bitx20:
raduino:
compliance:  <yawn>
etc.

This would make it easy to scan messages for those of interest without the burden of maintaining subgroups.  If the frequent posters adopted this convention, others reading the group would likely catch on.

Just my 2 cents.  I enjoy reading this group, let's keep it fun.

Chuck WB6GPO

Re: ATU for mBITX

Lee
 

I use an  LDG Electronics Z-11 Pro auto tuner.  It works very well.. 
-
Lee - N9LO  "I Void Warranties"

 

Re: ATU for mBITX

MVS Sarma
 

i find a cheaper  PVC gangs based  antenna tuner kit as sold by ebay.  For QRP  it should be fine. I know of friends who used  PVC gangs for antenna tuners.
regards
sarma
vu3zmv

On Thu, Aug 30, 2018 at 1:37 PM Raj vu2zap <rajendrakumargg@...> wrote:
What I am using with bitxs

http://www.ldgelectronics.com/c/252/products/21/49/1

Raj


At 30/08/2018, you wrote:
>Hi,I  want to add an antenna tuner for my micro bitx. which is the best?  Manual or Auto or Remote ATU? you suggestions and experiences please.
>73,VU3JYT,Rajan




Re: personal distance record with FT8 #ft8 #ubitx

iz oos
 

Come on, it's FT8, 10w and a wire antenna on the roof are more than enough for 13Kmiles SSB/CW contacts, although not everyday . Try that on the upcoming wwssbdx contest.


Il 30/ago/2018 04:20, "Don - KM4UDX" <dontAy155@...> ha scritto:
Reach is a function of antenna, and the weirdness of the heavens, etc. etc. etc.  All of 10w.  And so many of you have gone really far. I am but a grasshopper.

But it might be fun to get other distance records?  I was pleasantly surprised to see this.