Re: IRF510- Temporary replacement?
Ah, I have a BS170! Would it be a drop-in replacement, then? I'll check the data sheet I suppose. Thanks for the suggestion. -- Ryan Flowers W7RLF
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?<-- Learn how to go digital on the BITX40
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Allard was compiling your version 1.113 sketch and it says "Sketch uses 30,936 bytes (100)% of program storage space. Maximum is 30,720 bytes."
Maybe this was already addressed, if so sorry. Nice job on all the extras, thanks.
David KG7WFM
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Re: Low mic gain and rf power
I also had low mic input on both bitx40 that i built.
I added a mic preamp and it made the ssb transmissions have lots of audio with good clean audio.
I just used some cheap china module. A couple of dollars.
No more yelling in the mic.
Joe
VE1BWV
On Tue, Jun 6, 2017, 10:35 PM Jerry Gaffke via Groups.Io <jgaffke= [email protected]> wrote: The microphone amp is driving a very low impedance load, won't see much voltage gain?
across the microphone amp unless you remove C106.
See this post and the thread around it: ??/g/BITX20/message/22836
On Tue, Jun 6, 2017 at 06:23 pm, Arv Evans wrote:
The electret microphone should put out around 45 mv at normal voice levels.? The microphone
amplification stage has to make up the difference between that and what the BFO mixer needs
for full output.
?
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Re: IRF510- Temporary replacement?
On the bright side, ?you can use the down time to figure out how to water cool an IFR510.?
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Re: IRF510- Temporary replacement?
On the bright side, you can use the down time to figure out how to water cool an IFR510.?
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The said capacitor cleans up the POTs viper created noise and filters any induced RF signals on the wires that go from pot to raduino.
?The cap doesn't do any tuning . All the best ?regards ?sarma ?vu3zmv
On Wed, Jun 7, 2017 at 12:45 AM, <daniel.rahn@...> wrote: Craig,
The ceramic is used with the tuning pot. See the instructions at??? Step 3: Wire up the Raduino, connect the tuning pot --> solder the 0.1uF disc ceramic between the yellow and violet wires on the tuning pot.
I'm still trying to figure out what the surface mount cap is for...please do let me know if you find out!?
-Dan
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Re: Calling West Coast BITX operators
I wonder if the folks in the Portland/Vancouver area would be interested in getting together... I've been trying to figure out how to gather together some other QRP and builder types (bitx40 or not) in this area to help each other, swap parts, talk about projects etc... if anyone is interested, let me know and we will figure out how to put something together. 73 de bill
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Re: Low mic gain and rf power
The microphone amp is driving a very low impedance load, won't see much voltage gain? across the microphone amp unless you remove C106. See this post and the thread around it: ?? /g/BITX20/message/22836
On Tue, Jun 6, 2017 at 06:23 pm, Arv Evans wrote:
The electret microphone should put out around 45 mv at normal voice levels.? The microphone
amplification stage has to make up the difference between that and what the BFO mixer needs
for full output.
?
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Gerry,
"it adds at least 10k ohms between the audio out and the speaker", where are you attempting to install the VU2ESE AGC circuit ??
Both the VU2ESE and the VK3YE AGC circuits act by shunting the audio signal around the volume control, the VU2ESE using a FET as the active shunting element and the VK3YE circuit using an LDR (driven by a LED) as the active shunting element. Neither of these circuits acts directly on the audio signal between the audio output and the speaker.
There was an informative post made in the last few months of one of our number who tried both the VU2ESE and the VK3YE AGC circuits. He found that for him the VK3YE circuit was the best/ easiest to set-up and had the most pleasing AGC action. Just search the past posts looking for AGC + VK3YE.
Best of luck,
Peter VK1XP
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On 07-06-2017 04:33, ohwenzelph via Groups.Io wrote: Hi,
Has any one built Ashhar's agc circuit and had it work? Seems it adds
at least 10k ohms between the audio out and the speaker, if I add that
much resistance I get no sound out of my speaker. Maybe I don't
understand where it is placed. Also in the photo it seems the exciter
and collector of the 2n2222 or 2n3904 are switched relative to the
schematic. Any help appreciated. I have not tried VK3YE's yet, though
it seems it would add at least 4.7k
Thanks,
Jerry AA1OF
Sent from my iPad
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Re: IRF510- Temporary replacement?
Ryan
There are a number of small MOSFETS like the 2N700x and BS170 that should work fine
for QRPp operations.
Arv
_._
On Tue, Jun 6, 2017 at 7:21 PM, Ryan Flowers <geocrasher@...> wrote: Thanks Arv, I appreciate that. That's what I am interested in too. If I could get 100mw out with a 2n7000, I'd do it just for fun while I wait on the IRF510's to show up. I'm willing to experiment as long as I don't blow out any other parts in the radio ;)
--
Ryan Flowers W7RLF
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?<-- Learn how to go digital on the BITX40
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Re: Low mic gain and rf power
Jirka? OK1IEC
The electret microphone should put out around 45 mv at normal voice levels.? The microphone
amplification stage has to make up the difference between that and what the BFO mixer needs
for full output.
Arv? K7HKL
_._
On Tue, Jun 6, 2017 at 4:13 PM, ekelley <ekelley828@...> wrote:
I have the same problem with 2 of my Bitx40's.
Ed W0OIC
On 6/6/2017 5:29 AM, Jirka wrote:
Hello everybody.
?
My name is Jirka,
callsign OK1IEC, and I am new in the group. Recently I bought
BITX40v3 and built it in the Al box. RX is ok, comparable? with
my K2 in normal conditions. The problem is with transmitting ¨C I
am not able to reach more than about 1W of output power shouting
very loudly into electret mike. Mike change does not help, pot
R136 is in the full gain position.
I? decided to do
some measurements: I? used Audacity software to produce 1 kHz
audio and connected it to Mic pins of BITX40 via 47uF
capacitor.? I need 280mV p-p AF signal to get 6W RF output power
on my dummy load.
AF signal
levels:?? Mic (C121): 280 mV p-p;? C122: 410
mV p-p
RF signal levels: C132: 1.3V p-p;? C134: 3.45V
p-p;? C141: 3.25V p-p; C152: 8.6V p-p; C155: 51V p-p; Antenna:
50V p-p.
It seems the RF chain is ok but? AF stage Q12 has
suspectly low gain. Components seem to be ok, Q12 Uc=10V,
Ue=2.26V
Any idea or advice appreciated. ?
73! Jirka
?
Trafo T4 in BFO mixer ??? BTW I see the
difference between schematic (D15, D16, R106) and real
components on the pc board.
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Re: IRF510- Temporary replacement?
Thanks Arv, I appreciate that. That's what I am interested in too. If I could get 100mw out with a 2n7000, I'd do it just for fun while I wait on the IRF510's to show up. I'm willing to experiment as long as I don't blow out any other parts in the radio ;) -- Ryan Flowers W7RLF
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?<-- Learn how to go digital on the BITX40
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Re: 300Km with a bicycle and my Bitx40
Looks like an interesting trip. ? You might want to look at an end fed half wave antenna EFHWA so you don't have to pack the fishing rod. You can find plenty of plans and kits online. ?I am using this one?
qrpguys.apps-1and1.com/end-fed-half-wave-sota-antenna-tuner
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Re: IRF510- Temporary replacement?
Ryan? W7RLF
Any of the IRF series (IRF-510, 520, 530, 540, etc) should work to some extent.? Some of
them may have higher drive requirements due to higher input capacitance, but in an emergency...
Other of the IRF series may also work a bit, as long as they are N-types so the polarity will be
correct (IRF840 might be interesting).? You can find MOSFETs in many salvaged PC power supplies.
Might even be able to parallel up 3 or 4 of 2N7000 and get 0.5 watts or so output.
Arv? K7HKL
_._
On Tue, Jun 6, 2017 at 7:08 PM, Ryan Flowers <geocrasher@...> wrote: Thanks Jerry. Yeah, I'll just wait it out! I have a pretty beefy heat sink on it, but I think it just can't handle WSPR's 2 minutes of full-tilt-boogie at the higher voltage. Oh well, that's what experimenting is all about. Thanks again!
--
Ryan Flowers W7RLF
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?<-- Learn how to go digital on the BITX40
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Matt W5LL
Is it possibly locked in transmit mode due to wrong connection of the attachment wires?
Arv K7HKL
_._
On Tue, Jun 6, 2017 at 4:44 PM, Matt Patterson <W5llmatt@...> wrote: Did this and still it even a hint of sound.? Tried a different speaker too that I know works.? Frustrating....
At this point I'm going chalk it up to lesson learned.? I thought this would be a fun build but it's turned into another headache that I don't need right.
73 Matt
W5LL
Sent from my iPhone 7
> On Jun 6, 2017, at 5:39 AM, Raj vu2zap <rajendrakumargg@...> wrote:
>
> Matt,
>
> Check the speaker first with your meter on continuity / beeper setting.
>
> Your volume control may be the problem. Just short the brown and red wires and see with volume set at max.
> Mine packed up when I tried to tin the leads!
>
> Raj
>
> At 06-06-2017, you wrote:
>> First time builder here.? Got my bitx40 all together.? The unit powers up but I hear no static.? The instructions say I should hear a low hiss even without it connected to an antenna.? ?I hear nothing.? Anyone have an idea on where to start?? Failing that, anyone want a project?? I should just stick to built rigs.? I have poor eyesight and suffer from headaches all the time so I'm sure it's something I did. :(
>>
>> 73 Matt
>> W5LL
>
>
>
>
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Re: IRF510- Temporary replacement?
Thanks Jerry. Yeah, I'll just wait it out! I have a pretty beefy heat sink on it, but I think it just can't handle WSPR's 2 minutes of full-tilt-boogie at the higher voltage. Oh well, that's what experimenting is all about. Thanks again! -- Ryan Flowers W7RLF
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?<-- Learn how to go digital on the BITX40
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Re: IRF510- Temporary replacement?
If desperate for something to play with while waiting for some IRF510's to arrive,
might try removing C152, C155, C156, ?then add a 0.1uF cap from T6-5 to C160
So skipping the IRF510 entirely, driving the low-pass-filter from the 2n2219a.
Might get 50mw out. ?Or might blow Q14.
Probably best to sit on your hands.
I bet 19v into the IRF510 continuous duty blew the IRF510 due to heat.
Heat conduction from IRF510 die to tab is not ideal for this kind of service.
If the IRF510 is warm to the touch, the die inside is smoking hot.
A bigger heatsink might help, and/or stick with 12v for continuous duty.
Or have a dozen IRF510's on hand.
Jerry, KE7ER?
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On Tue, Jun 6, 2017 at 04:51 pm, Ryan Flowers wrote:
I blew out the IRF510 (still not completely sure how- might have been because I was doing WSPR with 19v on the PA?) and so while I source a replacement, can anyone suggest any other transistor/fet that can be used in its place? I don't care if it puts out only a 100mw, that's okay with me- I just want to be able to transmit in any capacity. I have some NPN and PNP transistors about and am wondering if one of those would be workable. Thanks :)
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Re: Europe to States BitX QSO
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Quality speaker mic with minimal modding
Does anyone know of a decent quality speaker mic that does not require a lot of modification to use? ?I would like something that is a step or two up from the baofang mics. ?I want my radio to sound good and I would like my voice to come out better on the other side.
I am fine with installing a jack for the speaker mic in the enclosure.
Thanks in advance.
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I've just released raduino_v1.14, download it from New in this version:
- added VFO A/B monitoring mode (press Function Button 5 times)
- use RX-offset instead of TX-offset in CW mode - the display now shows the correct TX frequency in CW
- changed the way to switch from CW to SSB mode: press PTT to return to SSB mode (tks Willy W1LY)
- restored the functionality for old way calibration method
- simplified the method for sidetone setting: hold key down to hear sidetone
- improved the display during "fast scan" at tuning pot limits (tks Paul KC8WBK)
73, Allard PE1NWL
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bill
Allard PE1NWL