Date   
Ubitx latest version board.. I need more audio to the speaker..

Kevin Rea
 

Hi guys,
I just got through building my UbitX transceiver.
Is there anyway to get more audio to the speaker..
I mean I hear it and good stuff like that, i would just like more audio.
I am using a 4ohm speaker.

kevin rea
lancaster, calif.
k6rea

Re: End Fed antennas w/ uBITX #ubitx

Warren Allgyer <allgyer@...>
 

Allison

i agree with most of what you said. 

I have made extensive tests of the most commonly used 49:1 transformer as well as VNA analyses of both random and resonant end fed wires. I have not tested 9:1 transformers. 

90% and higher losses occur using the 49:1 transformer on non-resonant wires. If the wire is resonant the losses drop to on the order of 20%. In both cases the measured VSWR is severely and favorably distorted by the transformer losses.

What you you say about harmonically related bands is true in theory but not useful for the directly related HF bands because of the shortening effect of multiple half waves in series. This causes the second harmonic resonant point of, for example, an EFHW wire resonant at 7.1 MHz, to be well
above the 20 meter band. The wire therefore when used on 20 meters will be operating in the non-resonant mode with resulting 90% or more losses.

The EF wire itself, both in resonant and non-resonant configurations is an excellent radiator. The challenge is to deliver power to it effectively. This can be done very well if the wire is resonant with a transformer. It can also be done very well across a range of bands if a tuner is used rather than a transformer.

If  you put 100 watts into a non-resonant antenna fed by the popular  49:1 FT-250-43 toroid transformer, key down for one minute, the transformer will be too hot to hold. If you do it at 500 watts the core will explode. On the other hand, used with a resonant wire and on bands 40 meters and above, the transformer will be Weston but not alarmingly so. 

Re: End Fed antennas w/ uBITX #ubitx

ajparent1/KB1GMX <kb1gmx@...>
 

Jim,

The vertical for 2M on the truck is a halfwave end fed.  There are marine units for fiberglass boats.

I use the part EF40/02/10 and EF-QUAD (40/20/15/10) here.  I keep a EF40/20/10 in the antenna
bag in the truck a long with a vertical kit (poor girls pac12) and a assortment of cordage for
suspending things.  

A 1:49 transformer is likely adequate.  The end impedance of a resonant half wave follow the
same pattern as a center fed half wave dipole.  It varies with height and proximity to objects.

I also have a few monoband end feds that use a L-network for matching and are also very good.
I use them for 40, 20 and 10M.

Also I tend to keep clear of harmonically related coax lengths like 33ft/66ft  (I use 25, or 40ft) for
portable work however FD setups lengths like 75 and 100FT are used.


The big argument is and has never been do they work.  Its been about the return currents
on the shield of the coax.  That varies with the length and position where its measured.
Generally its low assuming the antenna is actually resonant.  If its not then it behave more
like a transformer fed random wire with much (significantly) higher shield currents.

My experience is every time I encountered a case locally of someone having RF issues
with an end fed.  The SWR was terrible and they were trying to fix it with the tuner
(rigs or external) and the wire was just plain wrong length.  Worst case was a 40M
monoband resonant at 6.1mhz.  The wire was low, inverted V with the middle maybe
25ft with the ends not more than 6ft up and the wire measured 68ft.  Another was
actually the EARCHI 1:9 53ft a very different beast (but its endfed!)...  Usually the
prior install was a dipole or G5RV with the same issues.

Given a bit of effort and care many antenna work well or are at least serviceable.
Things like RFI and hot mics are usually the result of installation related errors
or the entenna being just too close.

Allison

Re: End Fed antennas w/ uBITX #ubitx

Jacob Farnes
 

I took an opportunity to install a long piece of random wire on the roof of my QTH. Didn't measure the physical length with the limited time I had but later measurements put it at under 130 feet. (The original speaker wire was cut at 66-feet, the the pairs split and soldered. Not an ideal length but what I had on hand for a one-time opportunity. I may have clipped a few feet from it and forgot while it was in my portable kit.) Tucked it down under the tar shingles at the Ridgeline.

Brought one end to a junction box and used it for listening mostly. Longest wire i ever have had in the air. Used some Iron tripwire for four 40-foot groundplane wires as I needed to be as invisible as possible.

Many months later I got a RigExpert AA30.Zero to analyze my whole system as the T-match tuning wasn't making sense to my brain. Was averaging 200-ohms on each band at 40m and higher. So wound a 4:1 balun on a T152-2 core.  That dropped 40m-10m to 25-75 ohms plus reactance.

So I use a simple VK6 L-match with a T106-6 core on a 14-position switch (military surplus), a 365pF air-variable capacitor, and  some silver mica capacitors on SPST switches to add more capacitance as needed. It's not needed on 40m as that was 50-75 ohms.

As for actual antenna performance, I seem to do very well with NVIS on 80m & 40m. On days 40m goes long, I get into Texas just fine.

On the local HF net (from Boise to Pocatello to Idaho Falls & Rexburg, roughly 325 miles) I'm heard very well at 10W on the Bitx40 & uBitx and at 100W with the IC-718, even if local noise sources make it very hard to hear net control.

That's my end-fed I'm using. Kicks the pants off the tripwire dipole that was 18:1 SWR I was using before that as a cloud burner at this QTH

73 de Jacob AG7CT

Re: End Fed antennas w/ uBITX #ubitx

ajparent1/KB1GMX <kb1gmx@...>
 

Bo,

The 1:9 designs (not 9:1) can be very good or terrible.  Depends on the wire length the longer 53ft and up behaves better.
Also you do need a counterpoise or ground radial system.  I've used one of about 89Ft as a inverted L with ground plane
and for 160, 75, and 40M it was a very good antenna save for as a vertical and its ability to hear all noise.

If you go with 1:49, the wire must be resosnant as in a half/full/1.5/2 wave lengths and present Rx of
about 2500ohms with Jx of near zero (resonant).

Think of it as the ultimate off center fed Dipole.

Allison

Re: End Fed antennas w/ uBITX #ubitx

ajparent1/KB1GMX <kb1gmx@...>
 

WA8TOD,

There are two forms of end fed. 

Non-resonant with 1:9 transformer.  The idea there is to keep the SWR on the cable down to a dull roar.
Must use a counterpoise.  Depending on the transformer used the losses can be low or very high.  Also
wire length and height makes a big difference in presented impedance.

Resonant, these use a transformer to match the feedpoint impedance typically in the 1800-4000 ohms range.
Most relay on the coax as a return path.   The transformer matched types can operate on harmonically related bands
as a 40M half wave (about 66ft) is a fullwave on 20 and 2 full waves on 10M. With a strategic located tails or chokes
other bands like 15M and such are possible.   The trick is to make it look like a resonant piece of wire at some
multiple of a halfwave.  If the wire is resonant the transformer is a matching device.  If the devices are well designed
the losses are small.

If I were loosing 90% of the power the matching transformer would get very hot at 100W.

Allison

Re: Don't discount the rotary encoder as being at issue

Ashhar Farhan
 

These are standard encoders manufactured by ALPS and purchased in bulk from Mouser. We are constrained in our choice by only those that are detentless and have at least 22 steps per revolution. I do not have the model number handy but we have used the same since we switched to encoders from thr shuttle tuning mechanism.
If there are specific alternatives, we can switch to them. 
- f

On Wed, 25 Jul 2018, 06:35 Mike aka KC2WVB, <rb5363@...> wrote:
Sure, here it is. One more day and gmail would have erased my order confirmation. I have saved it as a screen shot since eventually others will need it too.

Thank you for placing your order with Digi-Key!
 
Your order is being processed. You will receive an email confirmation when your order ships.
 
 
 
Order Details
 
Your salesorder number is 54975240.
 
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PEC11R-4020F-S0012-ND
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On Tue, Jul 24, 2018, 8:22 PM BobS KE0REM <rshick@...> wrote:
Mike,
I have a brand new UBitx also and it too is inoperable, apparently due to the encoder.  One of my encoder terminals appears to be shorted to ground - hence the really spastic operation of the UBitx.  Same symptoms as yours, I'd bet, so a new rotary encoder is in my future too.  You mentioned purchasing five from DigiKey - can you provide me with the part number you ordered so I can repeat the order?  This appears to be another case of inexpensive (aka cheap?), untested components that have to be replaced to make the transceivers work.
Thanks in advance for your help - I hope the encoder fixes my transceiver as well as it did yours.
73, Bob

Re: End Fed antennas w/ uBITX #ubitx

Thomas Owens
 

A local ham was disposing of a SK estate and had a EFHW8010 for a great price. I purchased it and some other items from him, hung the EFHW8010 in the trees and was so pleased I ordered a EFHW4010 to take with me for travel, or field use. I figured I'd hang it in the attic for bad weather use. Testing it out with my 7300 (antenna is in my attic mind you), I got the following decode results on FT8 a few weeks ago. I think I'll keep it, thanks :)

Re: #ubitx #ubitx-help Not able to set up extension switches using CEC firmware #ubitx #ubitx-help

RCC WB5YYM
 

I just added 3 extension switches to my uBITX  last week with ver 1.08 and all worked well.  I did select the 5 sec delay, and  I did make a small wiring change just to make wiring more convenient for me. 

Re: Don't discount the rotary encoder as being at issue

Mike aka KC2WVB <rb5363@...>
 

Sure, here it is. One more day and gmail would have erased my order confirmation. I have saved it as a screen shot since eventually others will need it too.

Thank you for placing your order with Digi-Key!
 
Your order is being processed. You will receive an email confirmation when your order ships.
 
 
 
Order Details
 
Your salesorder number is 54975240.
 
DetailsAvailable QuantityBackorder QuantityUnit
Price
Extended
Price
 
 
PEC11R-4020F-S0012
PEC11R-4020F-S0012-ND
ENCODER ROTARY
 
Available
Quantity
Backorder
Quantity
Unit
Price
Extended
Price
 
13301.68000(USD) 8.40
 
1 of 1 parts displayed.
You’ve purchased these products.
Now stay up to date with PCN notifications by creating a My Digi-Key account.
 
 
 
 
Shipping Address
 
Richard Boyer

P.O. Box 108 
Gilboa, 12076
US
 
Billing Address
 
Richard Boyer

P.O. Box 108 
Gilboa, 12076
US
 
 
 
Order Summary
 
Items in Order:1
  
Subtotal:(USD) 8.40
  
Shipping:Unknown
  
  
Total:Unknown
 
VIEW ORDER STATUS
 
 
 
 


On Tue, Jul 24, 2018, 8:22 PM BobS KE0REM <rshick@...> wrote:
Mike,
I have a brand new UBitx also and it too is inoperable, apparently due to the encoder.  One of my encoder terminals appears to be shorted to ground - hence the really spastic operation of the UBitx.  Same symptoms as yours, I'd bet, so a new rotary encoder is in my future too.  You mentioned purchasing five from DigiKey - can you provide me with the part number you ordered so I can repeat the order?  This appears to be another case of inexpensive (aka cheap?), untested components that have to be replaced to make the transceivers work.
Thanks in advance for your help - I hope the encoder fixes my transceiver as well as it did yours.
73, Bob

Re: End Fed antennas w/ uBITX #ubitx

Warren Allgyer <allgyer@...>
 

The reason an end fed antenna “works” on multiple bands as indicated by low VSWR is because of high losses introduced by the 9:1 or 49:1 transformer. For non-resonant wires these losses are 90% or more.

The reason such antennas “work” from the standpoint of making contacts is that losing 90% of your power only reduces your signal by a little over one S unit.

The transformer in such antennas does not “match”. It masks the true VSWR. It is a lot like putting whiteout on the X-rays to cure a broken leg.

WA8TOD

Re: PCB Artwork hint

Tom, wb6b
 

Yes, the days of staring for hours at a light table with six layers of pin registered mylar, at four times actual size. Trying to figure out where to cut and pull up tape and pads to make a design revision. 

Absolutely true genius was demonstrated by many board designers as they, time after time, pulled off the impossible task of adding components and layout changes on an already overpopulated layout.

The allure of electric drafting erasers. Well, that's another topic. 

On a side note, a company I worked for designed their own graphics processor chips. They had layer plots hanging from the walls of a two story room. I was looking at one closely and noticed drawings of Dilbert and crew tucked into some the obscure areas of the top metal layer.

Tom, wb6b

Re: End Fed antennas w/ uBITX #ubitx

John
 

Hey Bo,
Since I'm still laid-up and on sick leave due to knee surgery, I have plenty of time to try out new ideas.  Frankly, I bored out of my mind.  I have extremely good luck with the antenna I've built - had it about a year or so - and used it with good results on SSB, FT8, and WSPR.  That being said, I will look into the 49:1 as mentioned here and maybe it will be the latest and greatest for me as well.  It's the building and trying part of the hobby that I like the most (even though it is sometimes the most frustrating), and I am always looking for another interesting project to try.  

73's
John W5JXN

Re: End Fed antennas w/ uBITX #ubitx

Bo Barry <bobarr@...>
 

John, I had the 9:1 version (but not at a resonant frequency length) and it required a tuner and I wasn't impressed. I've found the 49:1 to work much better. I plan to rewind the 9:1 to make it a true EFHW. Bo w4ghv

Re: End Fed antennas w/ uBITX #ubitx

Bo Barry <bobarr@...>
 

I'm HOA bound too and doing well with the practically invisible MyAntennas EFHW with my ubitx and Icom7300. 
I prefer it for the ubitx since its SWR is flatter than my G5RV (I've hidden in the trees). It needs a tuner for sure.
And actually the EFHW outperforms the G5RV.
If your lot is too small for the 80 meter version, shoot a line over one tree (hoping you have one) and hook each end of the antenna to your two eaves and hung high in the middle by the tree. Inverted slanting V. works great. Good luck Bo w4GHV

Re: End Fed antennas w/ uBITX #ubitx

Tom, wb6b
 

I use a 55 foot end fed 80 through 10 meter antenna. It is designed to be non-resonant. The impedance of the antenna is in the 300 to 600 ohm range so I feed it with a 1 to 9 impedance matching unun. The resonate end feds are usually fed with a 1 to 64 impedance unum. It should be noted with end fed antennas there still has to be counterpoise, very often it is the shield of your coax run providing that. So, it is a good idea to add a common mode choke before your coax enters your shack. In my case I wound 10 turns of coax through a large toroid. I, also, provided a good ground at the shield side of the cable for safety and static buildup. I only work 80m for a local net, so the tradeoff in my case is 55 foot of wire at 80m will have reduced efficiency over a full half wave dipole. But, it is invisible running just under the railing of an upper deck. On WSPR my beacon has been picked up as far as Antartica. 

Re: Don't discount the rotary encoder as being at issue

BobS KE0REM <rshick@...>
 

Mike,
I have a brand new UBitx also and it too is inoperable, apparently due to the encoder.  One of my encoder terminals appears to be shorted to ground - hence the really spastic operation of the UBitx.  Same symptoms as yours, I'd bet, so a new rotary encoder is in my future too.  You mentioned purchasing five from DigiKey - can you provide me with the part number you ordered so I can repeat the order?  This appears to be another case of inexpensive (aka cheap?), untested components that have to be replaced to make the transceivers work.
Thanks in advance for your help - I hope the encoder fixes my transceiver as well as it did yours.
73, Bob

Re: PCB Artwork hint

Jerry Gaffke
 

Kicad 5.0 is now out with many significant improvements
    http://kicad-pcb.org/blog/2018/07/KiCad-5--a-new-generation/



On Tue, Jul 24, 2018 at 04:20 PM, Robert Ogburn wrote:
I have been using DipTrace since it was introduced for home projects.  For 'aesthetics' I set the design rules for a generous keep away. 
Paul, I believe the expression is "pride in workmanship".

Re: PCB Artwork hint

Robert Ogburn
 

I have been using DipTrace since it was introduced for home projects.  For 'aesthetics' I set the design rules for a generous keep away. 
Paul, I believe the expression is "pride in workmanship".

Re: PCB Artwork hint

Robert Ogburn
 

You dinosaur, me pond scum...
Red Tape, Blue Tape, Black Tape, DIY pads.....6x8 foot tapeups...  Ah, the xxxx old days!