Re: SA/NE612 vs. TA7358AP IP3 & signal handling?
Many Thanks Mvs Sarma (VU3ZMV) !
Hi have redesigned my hardware with the data in the PDF and
results are improved, I can confirm the mixer conversion gain
(audio out) when RL is above 3.8k, below that point you got losses
in the detected audio.
I had 1k of load at the mixer output, now changed to 8k2 and got
some gain, also I left one RF section out the RF path as I was
getting compression due to over amplification, confirmed with your
data and working now as expected, with a clean and linear RF path.
In short: I was overloading the poor TA7385AP and the NE612 more
overloaded than the TA strangely the TA supported the overloading
better... (it was more "linear" than the NE with overload.)
Many Thanks!
El 04/08/17 a las 01:48, Mvs Sarma via
Groups.Io escribió:
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Here is the full
copy of the evaluation.
regards
?vu3zmv
i have some data?? on TA7358 evaluation by
JH5ESM,
Cosy MUTO
?it was a copy of html file
?I could not convert it to pdf how ever , the rf
performance section is? pasted here , tentative
permission of the original author.
Evaluation schematic of RF
section is shown in Fig.4.
Measurements were made by reading output voltage
amplitude by a
oscilloscope.
![RF
section under test]()
Fig.4
Evaluation schematic of RF section. Figure 5 represents the results
and 36.3[dB] gain is obtained. Note that the
input voltage is SSG
readout for 50[Ω] load, but in acutal, input
impedance of TA7358
RF
section is expected as 32.5[Ω]. Therefore,
actual gain is
determined by
38.4[dB].?
Transconductance is then calculated as
30.8[mS] and it is very agree
with estimated value from bias condition.
Maximum allowable input level is -37[dBV]
(=14.1[mVrms]=20[mVp]) and
it is very agree with single transistor
amplifier.．
?
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I use a push button switch, push once to talk, push again to receive.
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Re: Juliano n6qw vs Farhan vu2ese???
just for fun dear friend ---dont worry be happy ;) :)
Sorry I don't know what to make of this.? And watching the video made me seasick!
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Re: uBitx almost finished by Bore Lezaic into CM2KMK PCB
A option might be to have the coils made as an assembly line with one person responsible for one section of the coil. Also, a test jig to test each section as it is made. A bit more front end but a lot less rework.
Sent from my iPhone
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Re: Juliano n6qw vs Farhan vu2ese???
Sorry I don't know what to make of this. ?And watching the video made me seasick!
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On Mon, Aug 7, 2017 at 04:07 am, Dexter N Muir wrote:
My thumb gets tired from holding the PTT on my FT-470
I added a foot switch to my BitX-20 for field day, now I use it all the time. ? -- John - WA2FZW
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Re: BITX QSO Night, Sunday, August 6, 7pm Local Time, 7277 kHz in North America, 7177 kHz elsewhere
Many stations that I normally could hear were very weak, barely above the noise.
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My bitx only used portable so I use a switch ?marked r/t with a green led see photo?
On 7 Aug 2017 12:08, "Dexter N Muir" < dexy@...> wrote: My thumb gets tired from holding the PTT on my FT-470, and most desk mics have a lock-on option for longer overs. The tiny button supplied with the BITX40 kit, wired to one of the 2-pin plug assemblies, makes a usable PTT, but not a comfortable one - I'd like to have it toggle TX on and off, preferably as a menu item/option under the function button. Anyone done this? A code block/fragment? I've outlined a possible menu structure for use with an Encoder that includes this, but some other kind 'programmer-boffin' would need to code it - BASIC back it the 80's was the extent of my expertise there. Anyone interested? Dex, ZL2DEX
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Re: BITX QSO Night, Sunday, August 6, 7pm Local Time, 7277 kHz in North America, 7177 kHz elsewhere
Picked up what I believe was a "BIT-X rollcall" on an 8:30 CDT on a Sony SW receiver. I was just North of Capital Mall in Jefferson City. It was within 5 kHz of the 7277 kHz, but this is a 40 year old receiver, ?so the VFO display may need calibration.? My goal for next Sunday is to get audio of the session. To much noise to get callsigns, but I heard "we've got 9...let's take it from the top." ?- KL4JN - ?Greg
On Aug 6, 2017 6:22 PM, "John KC9OJV" < greusel@...> wrote: Calling CQ Bitx from Chicago KC9OJV
7.277
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In perusing the web, I noticed that Fox Delta has a new VFO in their lineup.
It features the Si5351 and is rather primitive compared to some of the work on this list.
But it has a couple of interesting features. It uses a PIC chip (and the hex code is freely available).
It has only 2 outputs (CLK0 and CLK1). And it has a transformer output of the signals, making
them floating and differential. That is perhaps the most interesting part...
john
AD5YE
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Juliano n6qw vs Farhan vu2ese???
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My thumb gets tired from holding the PTT on my FT-470, and most desk mics have a lock-on option for longer overs. The tiny button supplied with the BITX40 kit, wired to one of the 2-pin plug assemblies, makes a usable PTT, but not a comfortable one - I'd like to have it toggle TX on and off, preferably as a menu item/option under the function button. Anyone done this? A code block/fragment? I've outlined a possible menu structure for use with an Encoder that includes this, but some other kind 'programmer-boffin' would need to code it - BASIC back it the 80's was the extent of my expertise there. Anyone interested? Dex, ZL2DEX
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Beautiful!? Great work!
Dave, KI4PSR
On 8/6/2017 10:54 PM, Curt M. wrote:
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Hi guys, after
getting off to a rockie start with the first Bitx 40 that I
received the second one has been working great. I've had a few
QSO's with it so I'm pretty happy about that. Today I finally
drilled out a volume knob that I bought online and I think that's
the last thing I'm going to do to this radio.?
I installed 1.20.1, the diodes for front end protection along with
the capacitor to take care of the harmonics so unless something
earth-shattering comes out in a future firmware release, mine's
probably going to stay just like this. I posted a few pictures
below.?
Curt
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Hi John, not sure why they labeled that 18V but it's meant to be a separate power connection for the PA.?
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Re: uBitx almost finished by Bore Lezaic into CM2KMK PCB
We have tried all that. There are issues with that too. They dont count properly. Ten turns instead of 9 turns can completely wipe out the 10 meter band
On 7 Aug 2017 2:09 pm, "Mvs Sarma" < mvssarma@...> wrote: Farhan jee
?Ask them to use different colored wires for different coils, ?like Green would be 9T and blue would be 10T etc
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Re: uBitx almost finished by Bore Lezaic into CM2KMK PCB
Farhan jee
?Ask them to use different colored wires for different coils, ?like Green would be 9T and blue would be 10T etc
On Mon, Aug 7, 2017 at 12:59 PM, Ashhar Farhan <farhanbox@...> wrote: I am not sure that it would make it to hfsigs yet. pcb is a only a small part of the entire job to get it on hfsigs. it took me months to train the 'girls' to figure out the transformers, coils, etc. there are five different windings on the T30-6 toroids, they can easily mix up a 9 turn coil for a 10 turn coil. the logistics are daunting. Cost escalation can bring manufacturing peace, but that will defeat the whole point. It would be sweet if the board could be delivered at the 100 dollar mark. i would love that very much.
btw, just as a note. there are no restrictions on anyone kitting the ubitx. i hope somebody else does it soon enough. i'd like to buy one too!
- f
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Xtal filter mods with results
Xtal filter performance of my board #888. Each line is 500Hz - 3db BW is
~1.6Khz, 6Khz is ~ 1850Hz
Center line is 11.998 MHz
C25,26,27 was changed to 82pF, 3db BW is 2Khz and 6db BW is 2200Hz. The
BFO frequency may need to increased to
11.999 instead of 11.9985
73
--
Raj, vu2zap
Bengaluru, South India.
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Re: uBitx almost finished by Bore Lezaic into CM2KMK PCB
I am not sure that it would make it to hfsigs yet. pcb is a only a small part of the entire job to get it on hfsigs. it took me months to train the 'girls' to figure out the transformers, coils, etc. there are five different windings on the T30-6 toroids, they can easily mix up a 9 turn coil for a 10 turn coil. the logistics are daunting. Cost escalation can bring manufacturing peace, but that will defeat the whole point. It would be sweet if the board could be delivered at the 100 dollar mark. i would love that very much.
btw, just as a note. there are no restrictions on anyone kitting the ubitx. i hope somebody else does it soon enough. i'd like to buy one too!
- f
On Mon, Aug 7, 2017 at 12:02 PM, chris gress <Chrisg0wfh@...> wrote: One would be on my shopping list
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Re: uBitx almost finished by Bore Lezaic into CM2KMK PCB
One would be on my shopping list
On 7 Aug 2017 07:30, "alf" < fpdbase@...> wrote: Nice Job, multi-band 4 leg critter
Silly question, When does it appear on HFSigs?
73 Alf vk2yac
Ashhar Farhan wrote:
Here is a four-legged critter on my bench!
- f
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Re: uBitx almost finished by Bore Lezaic into CM2KMK PCB
Nice Job, multi-band 4 leg critter
Silly question, When does it appear on HFSigs?
73 Alf vk2yac
Ashhar Farhan wrote:
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Show quoted text
Here is a four-legged critter on my bench!
- f
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Raj vu2zap