Date   
Re: BITX QSO Afternoon/Evening, Sunday, June 10, 3PM & 7PM Local Time, 7277 kHz in North America, 7177 kHz elsewhere.

Skip Davis
 

Tom on my last sailboat I had an insulated back stay that worked very well, I also would hoist up a wire antenna made of 1/4 wavelength of wire fed with 1/4 wavelength of coax cut for 20 meters. I was going to try a screwdriver antenna but never got around to it.  On my previous sailboat I had a Perth Outbacker antenna. 

Skip Davis, NC9O

On Jun 11, 2018, at 13:26, Tom VE3THR <muzzmobility@...> wrote:

Was on the boat last night and only barely heard one station coming out of the noise.. need a bigger boat so i can plant some trees for my windom hihi. Anybody ever shunt fed an aluminum mast or verticle successfully? Stay safe with all those storms guys.
73 Tom VE3THR 

Re: Messed up removal of TDA2822

Sajid Rahum
 

Yes good pointers. I did exactly as noted; The challenge was the sucker was not very good as expected and would lose some solder behind.  Wish there was a small micro drill to push thru :).  Lessons learned for sure.

My challenge is I am partially sighted for past several years so using head magnifying glasses.  

Raj - thank you I confirmed it was connected to C75; it is good. phew!.  I will use the wired connection for my own ease.

Next is to build it up and confirm all is working then will cut the wires smaller than present.  Hopefully all goes well.

Much appreciated as always..... This is a great group.

Re: CB amplifiers RM-Italy KL203P

Roy Appleton
 

A little pricey at $730!


On Mon, Jun 11, 2018, 5:54 PM Dennis <dennis@...> wrote:
I have been using a RM Italy HLA-305v for a year or so. Passes the US requirements and was favorably reviewed by ARRL. I hooked up the uBitx to it and had no issues.

73, Dennis
W7DRW

Re: No Power

Ian Lee
 

G8HAV

W
Press CW Key and the screen (second line) should change as shown below.
(This is the same for stock firmware, CEC Firmware)
LSB A: 7.010.000     (receive)
    CW: 7.010.000     (when press cw key)
     TX: 7.010.000     (when press PTT)

If there is no change in the screen, check the CW Jack and CW Line. Especially, check the resistance part attached to CW Jack
If the screen changes as above, please check if you can hear the side tone and the relay sound from the speaker.

You can test it with the scope or spectrum analyzer as follows.
RX : 
  CLK0 : 11.9 to 12 MHz measurement
  CLK2 : It depends on your receive frequency and mode.
              if your mode is 'USB' and 
             44998500 + your Frequency = meaurement frequency
TX :
  CLK0 : 0 Hz (Sleep)
  CLK2 : TX Frequency +- (2000Hz because of applied side tone)

Ian KD8CEC

2018-06-12 4:09 GMT+09:00 G8HAV <g8hav@...>:

Thanks Allison and Lee.

There are no changes on the LCD screen. just TX and the frequency in use VFO A. CW is set to ST.

The CW-KCLK#2 R100, and it is not a clean waveform; Scope indicates about 100 mV average.

Hope this helps



--
Best 73
KD8CEC / Ph.D ian lee
kd8cec@...
www.hamskey.com (my blog)

Re: RF power chain mods and improvements..

Nick VK4PP
 

Hi, Hows this? 
I drilled 2 small holes in the board to feed the legs through for the 12v side of the FT50-43. I used a larger drill on the underside to just remove 5mm of the ground plane around the holes and then some pvc insulation tape over and the wires poked through.
on the RD side, I just connected to the pad of the removed feedback resistors...



Hope this is clear...

73 Nick VK4PLN

Re: CB amplifiers RM-Italy KL203P

Jim Strohm
 

Iz,

If you have questions about solid-state (SS) amp topologies, please know that the RM-Italy amps (as do darn near every HF SS amp ever made since 1970) closely follow the Helge Granberg designs for Motorola, starting about 1968 and continuing well past 2000.

These designs are easy to find on the internet.

But as to your questions, it's difficult to get much more than a decade (e.g., 3 - 30 MHz, or 10X) of bandwidth using the older designs.  To go lower than 3 MHz, you'll need more rust in your ferrites -- that is, larger cores -- in both the input and output, and that tends to limit your high-frequency usability.  Especially w/ those RM-Italy amps.  Just adding a capacitor won't do it -- you can pull the input down in freq., but you'll lose at least the same comparable bandwidth up top.

If you look at the Jerry Sevick (SK) W2FMI books, you'll find some ways to stretch your bandwidth.  They're pretty simple to achieve once you know what you're doing, and not too expensive, but take a great deal of study at first.  And these books aren't cheap.

My recommendation?  Pay somebody who's already mastered the techniques for their expertise and finished products.

I have a few funny stories about making bootleg SS CB amps from the early 1980s.  Based on those experiences, I suggest people BUY these amps new or used, or at least buy dead ones from the ham radio flea market, and then resurrect them. 

Dead ones usually go for about USD$5 or $10, and the parts needed for resurrection are easy to determine, source, and replace.

Yes, you still need lo-pass filters.

73
Jim N6OTQ

Re: No Power

Skip Davis
 

First of all did your UBITX TX when you were using the stock firmware? You haven’t said it worked on both RX and TX after wiring up or did I miss that in your post? If not then possibly you have connected the wires to the wrong pins on the jacks, there are pins that are switched out when a plug is installed. 

Skip Davis, NC9O

On Jun 11, 2018, at 09:27, G8HAV <g8hav@...> wrote:

Hi,
Having built  the uBITZ and been checking receive and all is well. Loaded KD8CEC version 1.8 and checked receive again.

Now tried CW TX but got no power out. Read all the topics on a previous 'No Power' topic and followed all the checks.
All TX voltages are present and the main oscillators must all be running as receive is working well.

Got a simple 10 MHz scope and checked the output from the MIC amp and CW tone to the mixer and I cannot detect any change of signal 
when operating the PTT and the CW key. 

I will wire up a MIC element and test the audio from that later.

Any ideas would be welcome as I am reasonably competent in fault finding; I may make a tone generator and inject a tone into the mixer to check for power out.
There is a CW  tone output on pin 15 which I think is where the Raduino is plugged into the motherboard. 

That's my next check.

Thanks

Re: Transmitter Mods

Dave de WS1ETI <docame12@...>
 

I would be grateful to take advantage of your generosity. Is your address on QRZ good?

Dave, WS1ETI

Re: Latest Build, Mods and results.

Skip Davis
 

Nice looking build Mike I like your enclosure. 

Skip Davis, NC9O

On Jun 11, 2018, at 18:28, Mharpen@... wrote:

Hello, I enjoyed by first build so much I built another one. Avoiding all of the mistakes of the first one. Attached are the photos, below are the mods and results.
TX: 1. Choke in series with R86.
       2. All emitter resistors in buffer, predriver and driver bypassed.
       3. Feedback resistor in PA increased to 600 Ohms.
       4. Output Xformer replace with 2:4 on BN43-202.
       5. Adafruit audio compressor in mic line with chokes to eliminate RF feedback.
       6. PA powered by buck boost at 13.8V the rest of the board by 12V battery.
RESULTS: 30W on 80 and 40, 20W on 20. RV1 adjusted to reduce output to 15W.
RX: 1. ND6T AGC installed (underneath main board) at K3 powered by 5V regulator chip.
       2. Additional stage of audio gain installed between Q70 and U1 to make up for loss due to AGC.
RESULTS: Plenty of audio!! and good AGC action.
       3. VE1BWV audio pop mod (similar to the one standard on the new ubitx) installed underneath the main board.
       4. To further enhance the pop suppression PIN 1 at K3 is grounded.
RESULTS: Sounds fine to me.
Trivial Mods: a red/green LED TX/RX LED is installed on front. A TX/RX relay to key an external PA is installed on the back.
Ya'll have a nice day. Mike N6CMY. 
<IMG_4256A.jpg>
<IMG_4259A.jpg>
<IMG_4261A.jpg>

Re: Transmitter Mods

Howard Fidel
 

Yes, and I still have enough parts for every uBitx sold.

On 6/11/2018 9:11 PM, Dave de WS1ETI wrote:
I would be grateful to take advantage of your generosity. Is your address on QRZ good?

Dave, WS1ETI


Re: Net Neutrality Ending

Richard Spohn
 

Also agreed. - Rich

On 6/11/18, Bo Barry <wn4ghv@...> wrote:
Agreed. Sorry



Re: Transmitter Mods

Tom Christian
 

Jerry, Fantastic tips!  Will follow up.  I'm keeping your comments in my notes as a great reference.  Wish I'd had that info before I fought (and lost) with R85 on both rigs..... At least the discreat version surrender worked.....:) Thanks!
Tom
AB7WT

Re: RF power chain mods and improvements..

ajparent1/KB1GMX
 

Nick,

Came though beautifly.   

When you power it up let us know how it works for you.

Thanks!

Allison

Re: RF power chain mods and improvements..

Kees T
 

Hey, that's looking a lot like my robust 12V 20W Amp .....except my output transformer is 1:2 turns ratio with the 1 turn made from copper tubing and the ferrite material is #61 (#43 runs too hot....wastes power).  I think there is also a pony in using a pair of RD06HHF1 MOSFETs for a robust 12V 10W HF Amp with a BN43-202 (couldn't find a BN61-202) with 1:2 turns using coax shield copper for the 1 turn. The single 12V 5W RD06HHF1 Amp uses a 1:3 turns ratio. They all work well on 6m too.

73 Kees K5BCQ 

Re: RF power chain mods and improvements..

Kees T
 

Almost forgot......back when I was testing "many" RF Amp output transformers I came across some handmade binocular cores sold by RF Parts. They are small and appear to work fine ..HOWEVER... a batch I bought had apparently been overheated in the "xyz corp" assembly house and had several of the small ferrite sleeves cracked. So if you go that route, beware. The cracked sleeves "don't work so good".

73 Kees K5BCQ

Re: RF power chain mods and improvements..

Satish Chandorkar
 

It seams that there is sufficient room to stack another T50-43 in the final transformer so as to ease stresses and heating of
the transformer while trying to get maximum output from it

Satish VU2SNK

On Tue, Jun 12, 2018 at 8:42 AM, Kees T <windy10605@...> wrote:
Hey, that's looking a lot like my robust 12V 20W Amp .....except my output transformer is 1:2 turns ratio with the 1 turn made from copper tubing and the ferrite material is #61 (#43 runs too hot....wastes power).  I think there is also a pony in using a pair of RD06HHF1 MOSFETs for a robust 12V 10W HF Amp with a BN43-202 (couldn't find a BN61-202) with 1:2 turns using coax shield copper for the 1 turn. The single 12V 5W RD06HHF1 Amp uses a 1:3 turns ratio. They all work well on 6m too.

73 Kees K5BCQ 


Re: RF power chain mods and improvements..

Nick VK4PP
 

On Mon, Jun 11, 2018 at 08:12 pm, Kees T wrote:
Hey, that's looking a lot like my robust 12V 20W Amp"
"All roads lead to Rome" and "When in Rome" ...

I suppost the end result is to have a PA in the uBITX like your 20W amp.
I had even concidered stripping out everything from RV1 and just installing your 20W amp or the Aussie Minikits 16W amp of similar design...

Good tip on the Output transformer. I used the 202 as it fit well and I really cant detect any heating. Maybe a BN61-202 would be even better... I grab a few in my next parts order.

Whats the difference in doing 1:2 with coax, or like I've done 2:4 with enameled wire?

73 Nick VK4PLN

Re: 2.5 MHz low pass fiilter uses no toroids, SMDs #ubitx

VK3HN
 

Good looking trace from a HPF made of surface mount inductors and capacitors. I'm not surprised by the use of s.m. caps but inductors does surprise a little.  I would have hand wound them on T37-2 (at a minimum).  Are they anything special Glelnn?  --Paul VK3HN.  

PS: I want a Rigol DSA815 (!)

Re: ubitx first power up

KM4TRT
 

Thanks folks for all your help.  I'll try the BFO route first, now that I know the approximate range, and if that doesn't work I'll mess with the IF

Andy.   KM4TRT

Re: RF power chain mods and improvements..

Nick VK4PP
 

Anonther thought: We could take out the 2 power chokes L8 and L9, strip them, stack them and bifilar wind them and use in the same way without having to buy an extra  FT50-43.

73 Nick