Date   
Re: I captured my own PSK31 signal and it is not a pretty picture #ubitx-help #filters

Dexter N Muir
 

I did this a couple of decades ago, for Packet. Also opto-isolated PTT (from RS-232 handshake line). Easy.

Re: Harmonics and Relay Replacement

Glenn
 

VK4PP 45Mhz Filter Boards. - AKA Simple spur fix

Nick VK4PP
 

Hi All.
Following on from https://groups.io/g/BITX20/topic/25208658
the filter boards are in, I will install one tonight and post up a PIC...

I have added them to my ordering page, price is ONE cent only, + postage.
Feel free to take up to 10 and also maybe sample the other warez...

VK4PP Order Form

73 Nick VK4PP

Re: Harmonics and Relay Replacement

Joe Puma
 

Mike this sounds promising. Thanks for the work and feedback. 

Joe




On Oct 8, 2018, at 4:51 PM, Gordon Gibby <ggibby@...> wrote:

Wow great work Mike!


On Oct 8, 2018, at 15:54, Mike Doty via Groups.Io <mikedoty@...> wrote:

I thought I would pass this along, for whatever it is worth.  I have two Ver 3 and one Ver 4 uBiTX rigs.  I have replaced K3, KT1, KT2, and KT3 relays with Axicom relays which has knocked down the 3rd, 5th, and 7th harmonic levels from -35dB to below -50dB on all 3 rigs without any board modifications to the LPF circuits.  This may be anecdotal but with 3 rigs showing the same results it may be something to consider.  I purchased the relays from Mouser - part # 655-V23105A5403A201.  Cost was $2.89 per relay plus shipping.  I've attached photos (sorry for the blurriness) showing the before and after results on my Ver 4 rig.
--73--  Mike  --  W0MNE
<v4_1 spec.jpg>
<v4_1 axicom spec.jpg>

Re: I captured my own PSK31 signal and it is not a pretty picture #ubitx-help #filters

Joe Puma
 

I would use the iso transformers like the ones they sell on eBay for audio. 

Joe 


On Oct 8, 2018, at 5:53 PM, Don - KM4UDX <dontAy155@...> wrote:

iz oos, I have a external USB soundcard connected with mini audio cables to the uBITX. And the normal usb cable between the laptop and the radiunio. 
Are you suggesting I need a "easy digi" type interface with isolation transformers to isolate the audio component? Or something else?

And thank you sooooo much for the help!!!!

Re: I captured my own PSK31 signal and it is not a pretty picture #ubitx-help #filters

Don - KM4UDX
 

iz oos, I have a external USB soundcard connected with mini audio cables to the uBITX. And the normal usb cable between the laptop and the radiunio. 
Are you suggesting I need a "easy digi" type interface with isolation transformers to isolate the audio component? Or something else?

And thank you sooooo much for the help!!!!

Re: Harmonics and Relay Replacement

iz oos
 

That's unbelievable! Wasn't the bad board layout causing it? Do the new version 4 have different relays and/or a different board layout?


Il 08/ott/2018 23:18, "Jim Sheldon" <w0eb@...> ha scritto:
I sent Mike a private email asking if these were pin for pin compatible.  While waiting for an answer I did some more research and find they ARE pin for pin.  They are also available at Digi-Key under the part# PB1055-ND for a couple of pennies less plus a bit cheaper shipping.  They are $2.81 each singly and $2.633 apiece in quantities of 10 each (enough to replace all 5 relays in 2 radios for $26.33 plus shipping.

I ordered 10 of them from Digi-Key and will replace all 5 relays in both of my V4 boards.  I'll run spectrum analysis on mine once I get that done and hopefully will duplicate Mike's indications.  Might be the simplest fix at least for the harmonic problem anyway.  Since I operate only CW, I'm not concerned with the SSB spurs anyway.

BTW, right now, both my V4 boards DO meet FCC spec with all harmonics -45 to -48 dBC on both boards.  I have NOT adjusted the factory set PA bias or the power controls as prior experience showed me that doing so was a great way to get the rig out of spec for sure.  

After changing the relays I'll do a complete bias adjustment on the PA transistors per the HF signals website instructions and check harmonics again.  If they are still in spec after that I'll play around with the power control while watching the spectrum analyzer to see what, if any changes occur.

I was recently given the use of an IFR A-8000 spectrum analyzer that was calibrated less than a month ago so I think the tests will be pretty accurate (after I learn how to use the beast! - LOL)

Jim Sheldon, W0EB

------ Original Message ------
From: "Mike Doty via Groups.Io" <mikedoty@...>
Sent: 10/8/2018 2:53:49 PM
Subject: [BITX20] Harmonics and Relay Replacement

I thought I would pass this along, for whatever it is worth.  I have two Ver 3 and one Ver 4 uBiTX rigs.  I have replaced K3, KT1, KT2, and KT3 relays with Axicom relays which has knocked down the 3rd, 5th, and 7th harmonic levels from -35dB to below -50dB on all 3 rigs without any board modifications to the LPF circuits.  This may be anecdotal but with 3 rigs showing the same results it may be something to consider.  I purchased the relays from Mouser - part # 655-V23105A5403A201.  Cost was $2.89 per relay plus shipping.  I've attached photos (sorry for the blurriness) showing the before and after results on my Ver 4 rig.
--73--  Mike  --  W0MNE

Re: Toroidal transformer values, toroids, windings, #ubitx #ubitx-help #parts

Doug W
 

Re: I captured my own PSK31 signal and it is not a pretty picture #ubitx-help #filters

iz oos
 

My guess is that you might have  ground loops between the radio and the computer.


Il 08/ott/2018 23:09, "Don - KM4UDX" <dontAy155@...> ha scritto:
So i finally got my SDR working at the same time as my uBITX while doing PSK31, and nothing blew up. Yea.
The picture shows big spikes off the center, if I read this right. 
Am I interpreting this frequency distribution correctly? I assume I should see a major spike and little else, correct?
Note, my sound card is at the lowest level I can set it. 
Is there something else I should do? I have to assume operator error is a major player here. hahah.

Re: Harmonics and Relay Replacement

Jim Sheldon
 

I sent Mike a private email asking if these were pin for pin compatible.  While waiting for an answer I did some more research and find they ARE pin for pin.  They are also available at Digi-Key under the part# PB1055-ND for a couple of pennies less plus a bit cheaper shipping.  They are $2.81 each singly and $2.633 apiece in quantities of 10 each (enough to replace all 5 relays in 2 radios for $26.33 plus shipping.

I ordered 10 of them from Digi-Key and will replace all 5 relays in both of my V4 boards.  I'll run spectrum analysis on mine once I get that done and hopefully will duplicate Mike's indications.  Might be the simplest fix at least for the harmonic problem anyway.  Since I operate only CW, I'm not concerned with the SSB spurs anyway.

BTW, right now, both my V4 boards DO meet FCC spec with all harmonics -45 to -48 dBC on both boards.  I have NOT adjusted the factory set PA bias or the power controls as prior experience showed me that doing so was a great way to get the rig out of spec for sure.  

After changing the relays I'll do a complete bias adjustment on the PA transistors per the HF signals website instructions and check harmonics again.  If they are still in spec after that I'll play around with the power control while watching the spectrum analyzer to see what, if any changes occur.

I was recently given the use of an IFR A-8000 spectrum analyzer that was calibrated less than a month ago so I think the tests will be pretty accurate (after I learn how to use the beast! - LOL)

Jim Sheldon, W0EB

------ Original Message ------
From: "Mike Doty via Groups.Io" <mikedoty@...>
Sent: 10/8/2018 2:53:49 PM
Subject: [BITX20] Harmonics and Relay Replacement

I thought I would pass this along, for whatever it is worth.  I have two Ver 3 and one Ver 4 uBiTX rigs.  I have replaced K3, KT1, KT2, and KT3 relays with Axicom relays which has knocked down the 3rd, 5th, and 7th harmonic levels from -35dB to below -50dB on all 3 rigs without any board modifications to the LPF circuits.  This may be anecdotal but with 3 rigs showing the same results it may be something to consider.  I purchased the relays from Mouser - part # 655-V23105A5403A201.  Cost was $2.89 per relay plus shipping.  I've attached photos (sorry for the blurriness) showing the before and after results on my Ver 4 rig.
--73--  Mike  --  W0MNE

I captured my own PSK31 signal and it is not a pretty picture #ubitx-help #filters

Don - KM4UDX
 

So i finally got my SDR working at the same time as my uBITX while doing PSK31, and nothing blew up. Yea.
The picture shows big spikes off the center, if I read this right. 
Am I interpreting this frequency distribution correctly? I assume I should see a major spike and little else, correct?
Note, my sound card is at the lowest level I can set it. 
Is there something else I should do? I have to assume operator error is a major player here. hahah.

Re: Harmonics and Relay Replacement

Gordon Gibby <ggibby@...>
 

Wow great work Mike!


On Oct 8, 2018, at 15:54, Mike Doty via Groups.Io <mikedoty@...> wrote:

I thought I would pass this along, for whatever it is worth.  I have two Ver 3 and one Ver 4 uBiTX rigs.  I have replaced K3, KT1, KT2, and KT3 relays with Axicom relays which has knocked down the 3rd, 5th, and 7th harmonic levels from -35dB to below -50dB on all 3 rigs without any board modifications to the LPF circuits.  This may be anecdotal but with 3 rigs showing the same results it may be something to consider.  I purchased the relays from Mouser - part # 655-V23105A5403A201.  Cost was $2.89 per relay plus shipping.  I've attached photos (sorry for the blurriness) showing the before and after results on my Ver 4 rig.
--73--  Mike  --  W0MNE
<v4_1 spec.jpg>
<v4_1 axicom spec.jpg>

Re: PTT for uBITX ?

Woody
 

Ah Ha!   Thanks...  I was looking at the main board schematic for T/R, not the Raduino T/R wiring.
Thanks,
Woody,  KZ4AK

On 10/8/2018 19:46, M Garza wrote:
To cause PTT, you need to go low.
PTT actually is happening via the Raduino and not directly from the transistor drivers.
Please look at the first image on this page: http://www.hfsignals.com/index.php/ubitx-wire-up/.
PTT is wired directly to the Raduino.

Hope this helps.

Marco - KG5PRT

On Mon, Oct 8, 2018, 2:20 PM Woody <mailme@... <mailto:mailme@...>> wrote:


I see many threads that indicate grounding (at MIC)
I plan to use a discreet PTT line to T/R
From the schematic, it appears that taking the input high
initiates PTT for TX.
All my stuff takes a PTT line low for TX.   I guess I will need to
invert.  Comments ?????


--

Re: Purchase of uBitx on hold until?

Dennis Zabawa
 

If what you have read is holding you back, perhaps you are really oriented more towards a production radio.  I personally would not count on seeing more than incremental changes, to the basic design, in the future.

Re: IF OUT uBitx sensitivity loss

iz oos
 

I solved! Q32 was fine. R36 was not. Its impedance turned out to be infinite. So I replaced it with a 560ohm (it should have been a 470) and sensitivity came back. A signal equal to S3 is easily audible now!


Il 07/ott/2018 21:16, "iz oos" <and2oosiz2@...> ha scritto:

I have just measured the sensitivity loss with an AD8307. Q32 instead of amplifying 7-8db it attenuates by the same amount, so total loss is about 15db as I estimated with just the S3 signal generator.


Il 07/ott/2018 15:41, "iz oos" <and2oosiz2@...> ha scritto:

Ah I said C31 but it was between R37 and C32. R37 is between R36 and C32 so what I have done is very close to your suggestion (R36). The strange thing is that I restored without the IF-OUT and I think there is around 15-20db loss. I tested with a small signal generator and the S3 signal I heard well before is now around noise floor.


Il 07/ott/2018 15:10, "Mvs Sarma" <mvssarma@...> ha scritto:
Sorry, I would have said R36. NOT R35



On Sun, Oct 7, 2018 at 5:59 PM iz oos <and2oosiz2@...> wrote:

Using a cheap tester, diode test, between the base and the emitter of Q30, Q31, Q32, Q70 I get around 850. Testing the other way round from the emitter to the base I get 1300 for Q30 and Q31 and nil at Q32 and Q70. Is that normal or is it an indication of a component failure?
Il 07/ott/2018 07:56, "Mvs Sarma" <mvssarma@gmail.com> ha scritto:
>
> You may better use a 0.01uF (10nF) from emitter resistor R35. The output could be taken through a screened cable and used. Only issue would be , if the load side of your add on equipment feeds any singal while in Tx mode, it would interfere the working of Tx.
> All the best
> sarma
>  vu3zmv
>
>  
>
> On Sat, Oct 6, 2018 at 10:56 PM iz oos <and2oosiz2@gmail.com> wrote:
>>
>> I tapped the IF before the 12Mhz IF between R37 and C31. The braid of the short coax was taken at R36. I used a block cap (3000pf) between the R37 and the buffer amp. The buffer amp was between the uBitx, attenuators and the softrock ensemble receiver. The estimated sensitivity loss is around 15-20db. I replaced the TDA2222 without any change. What might have been happened? TX output is fine.
>

Re: Harmonics and Relay Replacement

Clark Martin
 

What fundamental frequency was this for and have you tested other bands?  This is good news, thank you for trying it.

Clark Martin
KK6ISP

On Oct 8, 2018, at 12:53 PM, Mike Doty via Groups.Io <mikedoty@...> wrote:

I thought I would pass this along, for whatever it is worth.  I have two Ver 3 and one Ver 4 uBiTX rigs.  I have replaced K3, KT1, KT2, and KT3 relays with Axicom relays which has knocked down the 3rd, 5th, and 7th harmonic levels from -35dB to below -50dB on all 3 rigs without any board modifications to the LPF circuits.  This may be anecdotal but with 3 rigs showing the same results it may be something to consider.  I purchased the relays from Mouser - part # 655-V23105A5403A201.  Cost was $2.89 per relay plus shipping.  I've attached photos (sorry for the blurriness) showing the before and after results on my Ver 4 rig.

Re: Harmonics and Relay Replacement

Mike Doty
 

Thanks Jack.  I wish I could say that I discovered this intentionally but, to be honest, it was completely accidental.  I had removed the original relays from my first uBiTX while looking for a solution to the harmonics issue.  In doing so, I broke a pin on one of the original relays.  I had some of the Axicom relays in the junk box so I ended up sticking those in as replacements for all 5 of the relays.  When I put things back together and looked at the output I saw that the harmonics were all down below -50dB.  I still had 4 of the Axicom relays left in the junk box so I replaced the 4 relays on my second Ver 3 rig, leaving K1 in place.  I saw the same results.  To be sure that there wasn't something else involved before posting to the group, I ordered more relays and replaced the same 4 relays in my Ver 4 uBiTX.  Again, the same results.  I've attached pictures of the spectrum analyzer results for both of my Ver 3 rigs so you can see that it wasn't just coincidental. Unfortunately I didn't take pictures of the other two rigs before replacing the relays but they both originally had harmonics around -35dB before the relay swaps.  All of the spectrum analyzer results for each rig shown are on 40 meters at 10 watts with the SA span from 1 MHz to 100MHz but I cannot see any harmonics above -50dB on any band, 80 - 10. 
--73-- Mike

Re: Harmonics and Relay Replacement

Jack, W8TEE
 

Mike:

I'm a software guy and am a bag of hammers when it comes to the EE stuff, but this is very interesting to me, since we have so many people who are worried about the harmonics. Thanks for the post!!

Jack, W8TEE-

On Monday, October 8, 2018, 3:54:16 PM EDT, Mike Doty via Groups.Io <mikedoty@...> wrote:


I thought I would pass this along, for whatever it is worth.  I have two Ver 3 and one Ver 4 uBiTX rigs.  I have replaced K3, KT1, KT2, and KT3 relays with Axicom relays which has knocked down the 3rd, 5th, and 7th harmonic levels from -35dB to below -50dB on all 3 rigs without any board modifications to the LPF circuits.  This may be anecdotal but with 3 rigs showing the same results it may be something to consider.  I purchased the relays from Mouser - part # 655-V23105A5403A201.  Cost was $2.89 per relay plus shipping.  I've attached photos (sorry for the blurriness) showing the before and after results on my Ver 4 rig.
--73--  Mike  --  W0MNE

Alignment of Bitx40

craigmclean@...
 

Hello.

I just finished building my Bitx40 v3 board using a amateurradiokits.in case and a Baofeng mic modified as per 

https://drive.google.com/file/d/0B8v7bRFPZV71U3BVR28zUEdkN2M/view

The receive seems to work well.  I hooked the radio up to a receive loop antennas and was able to hear some local stations called CQ for a contest.  I then plugged the Bitx40 into a dummy load and put an ammeter in line with the power connection to do the alignment.  This is where things went a bit wrong.  

According to the Alignment of the Bix 40 section of this page

http://www.hfsignals.com/index.php/2017/11/23/wiring-up-the-bitx40/

I should adjust RV1 fully clockwise so the ammeter reads 0, however when I turn the radio on the ammeter immediately reads 150mA, no matter how I adjust RV1.  If I key down current jumps from 150mA to some other value depending on how RV1 is adjusted (between 280mA and 1A).  I also noticed that when I do the HAALOOOWW into the Mic current doesn't change at all even though I've keyed down (setting RV1 doesn't seem to change this at all).  I've also fiddled with RV136 which made no difference.

My PTT seems to be working, however I'm suspicious of the Mic.  I did check continuity from the pads of the electret all the way to the board and it is good.  The PTT and electret do share a common ground as per the instructions I linked above.

So basically two problems.
Receive current should be close to zero according to alignment instructions, but it's 150mA.  Also I push the PTT and current jumps a bit, but doesn't jump when I speak into the Mic.

Any thoughts?
Craig (VE6TBW).

Harmonics and Relay Replacement

Mike Doty
 

I thought I would pass this along, for whatever it is worth.  I have two Ver 3 and one Ver 4 uBiTX rigs.  I have replaced K3, KT1, KT2, and KT3 relays with Axicom relays which has knocked down the 3rd, 5th, and 7th harmonic levels from -35dB to below -50dB on all 3 rigs without any board modifications to the LPF circuits.  This may be anecdotal but with 3 rigs showing the same results it may be something to consider.  I purchased the relays from Mouser - part # 655-V23105A5403A201.  Cost was $2.89 per relay plus shipping.  I've attached photos (sorry for the blurriness) showing the before and after results on my Ver 4 rig.
--73--  Mike  --  W0MNE