Date   
Re: TDA 28222

MVS Sarma
 

Great  Daniel.
 please never insert stero head phones  while set is ON.
 once you have stero phones connected.  no issues to switch on.
  Failure (by short circuit ) happens only during insertion .
All the best sarma
 vu3zmv

Regards
MVS Sarma
 

On Fri, Jun 22, 2018 at 12:06 AM, Daniel Conklin <danconklin2@...> wrote:
Mine has the WX brand TDA2822.  I put a 6v regulator in the 12v supply line to the chip as suggested on this group and it has been working fine for a couple of months now.  The audio is loud and clear.  
Daniel, W2DLC


Re: Blown (socketed) TDA2822?

MVS Sarma
 

Thanks RAJ  sir.
The datasheets  whther suffix D or normal(dip) show test results all defined around 6 or 9V supply. and definitely not not at 12 or 13.8.

Thus most of us may have to reduce the supply to TDA2922 to say6V ( for 4 to 16 ohm speakers)

That would be a fiarpaly around V3 PCBs.

regards
sarma
vu3zmv

Regards
MVS Sarma
 

On Fri, Jun 22, 2018 at 7:40 AM, Raj vu2zap <rajendrakumargg@...> wrote:
Jerry,

I think its the TDA2822D that has been repackaged. See the specs attached!

Raj

At 21/06/2018, you wrote:
>The WX branded TDA2822 simply does not meet spec. 
>We have no idea what spec it meets, as WX does not have a datasheet for it.
>In addition to an apparent absolute max supply voltage of around 6 or 8v,
>it quite likely suffers in the audio quality department.




Re: Blown (socketed) TDA2822?

 

Jerry,

I think its the TDA2822D that has been repackaged. See the specs attached!

Raj

At 21/06/2018, you wrote:
The WX branded TDA2822 simply does not meet spec.
We have no idea what spec it meets, as WX does not have a datasheet for it.
In addition to an apparent absolute max supply voltage of around 6 or 8v,
it quite likely suffers in the audio quality department.

Re: smd Capacitor #bitx40

John
 

Thanks for that info Doug.
My board has a C107 in place at the balanced modulator, but a search shows that some boards were shipped with this cap missing. 
I guess they threw in a spare cap just to make sure.
--
John VK6JAH

Re: ND6T AGC and Click kit wiring notes

bands11
 

Hi folks … I noted the same issue on my AGC board … and then I looked at the pads on the bottom.  Of course the square pads (indicating the indexed pad ...   [ ]   0  ... ) were easily seen and when I took them to be the non-ground pad, everything fell into place.  I suspected that the “5v” legend was simply to identify the connection pair for power and ground … there was no room on the board to put it on the other end of the connection pair.

So ….. after discovering the index pin, everything got hooked up just fine.  :-)

Thanks again Kees!

Bob Harbrecht
KE7QEQ

On Jun 21, 2018, at 10:13 PM, Glenn <glennp@...> wrote:

Kees,
I think there is an error on the AGC pcb overlay. The hole marked as "5v" is actually ground. The hole adjacent is 5v.

glenn vk3pe

<KEE_S AGC PCB 5V _ GND REVERSED.JPG>
On Thu, Jun 21, 2018 at 05:14 pm, Kees T wrote:
I have updated the AGC/Click mini-kit "ordered/shipped" list in the "Files" section per today's information. There will be some delay before more kits can be shipped because I'm out of AGC boards and have just ordered another 160. I have plenty of parts.

73 Kees K5BCQ

ENGINEER … Solving problems you didn’t know you had in ways you can’t understand.   SigCat




Re: experience with Sunil VU3SUA's enclosures #ubitx

WA9PWR
 

I ordered one 4/6/2018 and received it in I think very roughly a month.
73, Bill WA9PWR

Re: Oscilloscope on sale

Ashhar Farhan
 

The Rigol DS1052E is a solidly built piece works really well, I only wish they had better quality probes.
- f

On Fri, 22 Jun 2018, 00:36 Ralph Mowery, <rmowery42@...> wrote:
I have had one like that for about 2 years.  It works fine for  the price.

ku4pt


On Thu, Jun 21, 2018 at 2:20 PM, Jack Purdum via Groups.Io <jjpurdum@...> wrote:
All:

Some here were looking for a good scope at a reasonable price. The Hantek 200MHz, 2 channel is on sale for $271.20. I have this scope an like it a lot.


Jack, W8TEE
_._,_.

Re: Homebrew from scratch #ubitx

Clark Martin
 

The best thing about standards is everyone implements them differently.


Clark Martin
KK6ISP

On Jun 21, 2018, at 5:57 PM, VK3HN <prt459@...> wrote:

Yes, absolutely, let's all propose an IEEE Standards Committee for HamBus, with meetings at exotic locations for the next 5 years..  And yes, the best thing about standards is there are so many to choose from.

experience with Sunil VU3SUA's enclosures #ubitx

Mike KK7ER
 

My young son got an Elenco FM radio kit for Christmas.  We built it together and now he is hooked.  He is studying for his technician license.
He has a birthday coming up so a few weeks back, I ordered a uBitX and one of Sunil Lakhani's cases.
The uBitX came in about a week.  Despite my credit card being charged immediately, I never received any acknowledgment of the case order.  I have tried to contact Sunil through several different channels but have gotten no response.  There were 12 of the cases in stock at the time of the order.  I am wondering if I should dispute the credit card charge or keep waiting.  What has been the experience of people in this group who have ordered cases from Sunil?  Has he come through?  What was time from order to delivery (in the US)?  Did you have trouble with communication about your order?

Thanks and 73,
Mike KK7ER

Re: Thoughts on a Ham Bus

VK3HN
 

My problem with the bus concept is that some but not all connections between analog modules are amenable to bussing.  

Control or signal lines that are needed by more than one module -- such as clocks, power, ground, control lines (+tx, +rx, band select, USB/LSB select, IF filter select, PTT, key, T/R relay) -- fit the bus model well.  Modules using these lines would not be location-dependent on the bus -- they could be plugged in in any sequence.  

The signal paths in a typical transmitter/receiver, however, are point to point and form a serial chain of modules -- eg. antenna T/R relay (and optionally LPF) -> BPF ->  RF amp -> Rx mixer -> xtal filter -> Product detector -> Audio preamp -> Audio filter -> Audio power amp.  I can't see an obvious answer to how to make these serial point to point connections on a bus.  

If I were to prototype this, I'd most likely run these signal paths in coax along the sides of the modules, not using the bus but floating the coax lines above the bus, between modules, perhaps with SMA or some connector type.  This compromises the bus model a bit (not all connections come in or go out of the edge connector/header, two module connection/disconnection points) but to put these connections on the bus complicates the bus and couples small signals and sensitive amplifier inputs to long parallel bus lines.

So the best I can imagine is a pseudo 'Hambus'. with control lines on the bus and signal interconnections not on the bus  

73 Paul VK3HN.    

Re: ND6T AGC and Click kit wiring notes

Glenn
 

Kees,
I think there is an error on the AGC pcb overlay. The hole marked as "5v" is actually ground. The hole adjacent is 5v.

glenn vk3pe


On Thu, Jun 21, 2018 at 05:14 pm, Kees T wrote:
I have updated the AGC/Click mini-kit "ordered/shipped" list in the "Files" section per today's information. There will be some delay before more kits can be shipped because I'm out of AGC boards and have just ordered another 160. I have plenty of parts.

73 Kees K5BCQ

Re: Thoughts on a Ham Bus

Rahul Srivastava
 

While formulating for a suitable HAM bus with current technology we have to consider many aspects. Most modern design will use mix of analog and digital technology, requirements become more critical when we throw in DSP and other features. Atlas bus in HPSDR was designed  with mainly digital signals running thru backplane. Such high speed signals between multiple FPGA's resulted in lot of cross talk. For BITX series with all the new enhancements ground separation becomes a critical issue. 

I feel for a simple design like uBitx , Elecrafts K2 approach suits us better with one main board with PA and other circuitry and provision for swap able plug in modules.  Si , mixers , PA, BPF  and LPF can be on main board. TIA and multiple stacked xtal filter modules can be swap able. Front panel can house the digital section ie Nano, LCD and controls. All boards to be plug in type.

73 

Rahul VU3WJM

Re: KD8CEC Firmware

Ashhar Farhan
 

The settings are carried over


On Fri, 22 Jun 2018, 08:40 Terence Taylor, <n6mon@...> wrote:
I am probably shortly going to be installing the KD8CEC firmware on my µBitx.
I do have one question, will the Raduino retain the alignment settings, or will I have to redo all of the alignment steps?




KD8CEC Firmware

Terence Taylor
 

I am probably shortly going to be installing the KD8CEC firmware on my µBitx.
I do have one question, will the Raduino retain the alignment settings, or will I have to redo all of the alignment steps?

Re: Understanding Spurious Emissions

Howard Fidel
 

Got it. Thanks. I never saw on my uBitx the numbers you reported, but I don't think it is a serious problem for a barefoot uBitx, which is the main point I was trying to make. It seemed like the group was spending a lot of energy on something that is like driving 60 MPH in a 55 zone.

On 6/21/2018 7:22 PM, ajparent1/KB1GMX wrote:
Howard,

The mixer where the spur is generated is the mixer formed by T2/T3 that is about 
28db (after allowing for filter losses and all)  later in the stream and if that mixer
is overloaded you get the spur.  The driving modulator is then underdriven.

Work it backward.  If that mixer is overloaded at -7 oir -10DBM what got to be
happening well before that?   And that mixer can easily be driven to its 1DB
compression or worse without hurting the audio to the ear.

Allison


Re: RF Situation Resolved.

Howard Fidel
 

Glad to help.

On 6/21/2018 4:03 PM, Latham, Chip wrote:
Howard (WB2VXW) called this morning and we went thru quite a bit of testing and things were not added up, until I mentioned that I had replaced the heatsink, made sure it was isolated from ground but forgot the FETs needed to be isolated from each other as well.
Thanks Howard, that was a stupid mistake on my part. I own it!
Farhan forgive me for suggesting there might have been a possibility of rushing the board out, getting ready for the release of V4.0
Chip
N5FJK


Re: Encoder problem

Howard Fidel
 

So there are several possibilities. I had the same problem initially, when I realized that I didn't wire it correctly. I fixed the wiring and it worked. It could be a bad encoder, incorrect wiring or a bad Raduino, or corrupted software. If you have a two channel scope you can look at the two outputs signals, they should create 2 pulse trains shifted be 90 degrees when you turn the knob. The phase shift reverses when you change direction. Most likely if both have pulses they are phased correctly, but if one or both don't, it wont work. If you see the pulses, it is not the encoder.

Howard

On 6/21/2018 4:32 PM, n7nsd@... wrote:
And yes, rotating only causes the display to flicker the last two freq digit from zero to fifty. After pressing the encoder and getting the change band option, turning causes no change. Same with the next press and then back to 40m where it won’t change freq. 


Re: Thoughts on a Ham Bus

Tim Gorman
 

I think you have hit on the only standard that would work for amateur
equipment.

I have used this type of construction for several pieces of equipment.
The pcb's can be shielded using cheap copper flashing from Hobby Lobby
using either feedthrough capacitors or rg-174 with the coax shield
soldered to the flashing where it goes through it.

A 100mmx100mm is about 4"x4". That's large enough for almost any stage,
be it rf, if, or audio. If we could standardize on interconnect design
between modules I'm not sure anything better would be needed.

tim ab0wr


On Thu, 21 Jun 2018 17:12:32 -0700
"Glenn" <glennp@...> wrote:

my thoughts, as indicated in these posts  its very hard to come up
with a 'universal' BUS.

I think a BUS suited to the project in  hand like uBITX, or one with
a similar 'block diagram' is a better idea.

And, I believe, it needs to take into account, the price of PCB's.
The 100x100mm size is the magic size for good deals out of China and
perhaps the bus should consider this as a standard size PCB. OK, it
will probably mean more 'blocks' are on each of these larger pcb's,
but even so, still leave some room for change.

glenn vk3pe


Re: Audio feedback during transmit? #ubitx

Mark M
 

Mine started doing it when I installed the ND6T/K5BCQ AGC board. It's not a ground issue, when I remove the board it stops. It looks to be correctly wired but I suppose I coulda fried something...it was my first real SMD assembly effort. It happens even with the board not connected to the RF path, i.e. just 5v and VOL-H connected. I suspect I screwed it up somehow. Maybe I'll assemble the second one I have and see if it works any differently.

Mark     AA7TA

Re: Homebrew from scratch #ubitx

VK3HN
 

Yes, absolutely, let's all propose an IEEE Standards Committee for HamBus, with meetings at exotic locations for the next 5 years..  And yes, the best thing about standards is there are so many to choose from.

My problem with the Hambus concept is that some but not all connections between analog modules are amenable to bussing.  

Control or signal lines that are needed by more than one module -- such as clocks, power, ground, control lines (+tx, +rx, band select, USB/LSB select, IF filter select, PTT, key, T/R relay) -- fit the bus model well.  Modules using these lines would not be location-dependent on the bus -- they could be plugged in in any sequence.  

The signal paths in a typical transmitter/receiver, however, are point to point and form a serial chain of modules -- eg. antenna T/R relay (and optionally LPF) -> BPF ->  RF amp -> Rx mixer -> xtal filter -> Product detector -> Audio preamp -> Audio filter -> Audio power amp.  I can't see an obvious answer to how to make these serial point to point connections on a bus. 

If I were to prototype this, I'd most likely run these signal paths in coax along the sides of the modules, not using the bus but floating the coax lines above the bus, between modules, perhaps with SMA or some connector type.  This compromises the bus model a bit (not all connections come in or go out of the edge connector/header, two module connection/disconnection points) but to put these connections on the bus complicates the bus and couples small signals and sensitive amplifier inputs to long parallel bus lines.

So the best I can imagine is a pseudo 'Hambus'. with control lines on the bus and signal interconnections not on the bus   Any comments?

73 Paul VK3HN.