Re: BITX40 with QRPLabs VFO
Hi
> On my QRP-LABS DDS VFO, my correction came out to 27.010.5. So it?> was a matter of fiddling with it, and I was able to tune it in by listening to? > a known station frequency like East Cars, and calibrating the vfo so it? > sounded natural. Finally I got an on air check with my buddy cross town.? > All good. BTW I have the new corrected software on the way.
If it all works fine and you're happy with it, that's fine. But just FYI...
The 27MHz crystal in the QRP Labs Si5351A Synth kit usually oscillates between 27.003 and 27.005. I have never heard a case of it oscillating as high as 27.0105. To be absolutely correct what you would need to do is adjust the programmed IF frequency to the actual BFO frequency of your BITX40. You probably entered "IF Offset" parameter "-012,000,000" but in reality the actual BFO frequency of your BITX40 will be a kHz or more lower than that. So what you have done by setting such a high "Ref Freq" parameter (27.0105) is cancelled out the error in the IF you entered. But the cancellation will only be perfect at one particular frequency.?
It's not important - because the BITX40 only operates over a narrow frequency range anyway. I'm just saying, to really be technically perfect one should adjust the BFO frequency as well as the 27MHz Ref Freq. But I know that is not necessarily easy if you are doing it by listening to a known station frequency.
73 Hans G0UPL
|
Looking from the front of the rig what are the correct pot connections - left to right. Red Brown Black or Black Brown Red?? Thanks - Noel
|
Re: BITX40 with QRPLabs VFO
Connections between the VFO and the Bitx are Clock 0, ground, the to the 2 pin connector next to the vfo coil approximately in the middle of the board. You have to remove ?the VFO coil as per instructions. I also put a 40 meter low pass filter in series with the VFO lines and the BitX connection. I'm not sure it made any difference, however it should turn the VFO square wave into a sine wave, and it's said to cut down the noise generated by the VFO.?
|
Re: BITX40 with QRPLabs VFO
On my QRP-LABS DDS VFO, my correction came out to 27.010.5. So it was a matter of fiddling with it, ?and I was able to tune it in by listening to a known station frequency like East Cars, and calibrating the vfo so it sounded natural. Finally I got an on air check with my buddy cross town. All good. BTW I have the new corrected software on the way. ?
|
Re: Improved audio from the Bitx40 (video)
Yes, could have done that. ?
But wasn't bothered to remove the board when the capacitors could just be soldered on the top side!?
|
Re: Improved audio from the Bitx40 (video)
Hi Peter,
Wouldn't it be better to remove the 47pf C102 all together and short the terminals together, then put a 2-40pf trimmer cap back in place where it is missing? Then you could adjust it while watching the audio analyzer and listening to the receive audio. I was already planning on doing it so I could accomplish the same thing you did. Joel Caulkins KB6QVI
toggle quoted message
Show quoted text
On Jan 1, 2017, at 7:28 PM, parkerp@... [BITX20] < BITX20@...> wrote:
?
(I think Bill might have mentioned this on Soldersmoke but I can't find the reference)
My Bitx has C102 as 47pF and no carrier frequency adjust trimmer (C103).?
It sounded very slightly bassy, lacking highs. ?The area around 2kHz is important.?
Most people wouldn't notice it but at QRP your audio band pass needs to be optimum to be heard on SSB.?
In short, I got better audio by removing C102's 47pF chip capacitor and substituting 27pF. ?Either a 27pF disc ceramic or 22 + 4.7pF. ?
Reports from other stations have been complimentary.?
This video discusses these topics in detail.?
73, Peter VK3YE
| | | | | | One or two capacitors can improve transmit and receive audio if your transceiver is misaligned or doesn't suit your voice. Find out how by watching th... | | | | Preview by Yahoo | | |
|
Re: Can I just buy the The Raduino??
CPD,
& I just needs an exiter for some mods...
Will it be OK for U if I send U ?Raduino?
Here already got 8 diffrent kind of DDS...
'Repair & Reuse or Recycle E-Waste'
On Jan 2, 2017 9:08 AM, " hsojhcoom@... [BITX20]" < BITX20@...> wrote:
?
Would just like to buy the Raduino, is there someone i can email or get a hold of so that i can just purchase the Raduino right from the ?
thanks in advance
73,
KE8CPD?
|
Improved audio from the Bitx40 (video)
(I think Bill might have mentioned this on Soldersmoke but I can't find the reference)
My Bitx has C102 as 47pF and no carrier frequency adjust trimmer (C103).?
It sounded very slightly bassy, lacking highs. ?The area around 2kHz is important.?
Most people wouldn't notice it but at QRP your audio band pass needs to be optimum to be heard on SSB.?
In short, I got better audio by removing C102's 47pF chip capacitor and substituting 27pF. ?Either a 27pF disc ceramic or 22 + 4.7pF. ?
Reports from other stations have been complimentary.?
This video discusses these topics in detail.?
73, Peter VK3YE
| | | | | | One or two capacitors can improve transmit and receive audio if your transceiver is misaligned or doesn't suit your voice. Find out how by watching th... | | | | Preview by Yahoo | | |
|
to bat for thr ft817nd, its big compromise is the speaker itself. a larger speaker helps. my main complain about it is the rx current consumption
On 02-Jan-2017 8:23 am, "Kent Vanderploeg kvanderploeg@... [BITX20]" < BITX20@...> wrote:
?
I did not activate the attenuator or the IPO.? I wanted it to be as apples to apples as possible. ? I can also turn down the RF gain and run up the AF gain for some of those buried signals. ? The noise is definitely there, ?but the 817 has a few extra tools to deal with it. ? I'm sure the larger speaker I'm using on the BITX helps too.?
Kent W9WB?
|
And Tom,
Please leave the previous replies below so we know to which message you replied to!
Cheers
Raj
toggle quoted message
Show quoted text
At 02/01/2017, you wrote:
Got it, thank you. I couldn't find the pot wiring on the schematic showing the wiper.
73
Tom
|
Tom,
The 10 turn pot has the diagram engraved on the body next to the leads. It is just that
the center wiper is at one end instead of the middle.
Raj
toggle quoted message
Show quoted text
At 02/01/2017, you wrote:
Got it, thank you. I couldn't find the pot wiring on the schematic showing the wiper.
73
Tom
|
Re: It stopped transmitting
Bill,
One question, when you switch to transmit does the current jump to 1A
when you speak into the mic or without speaking?
Raj
At 01/01/2017, you wrote:
toggle quoted message
Show quoted text
?
- At 31/12/2016, Bill Kittilson
bill@... [BITX20]
wrote:
- >
- >
- >I managed to kill my bitx40. It was working great until I decided
to tune up the big rig. I can still receive. No power at all on transmit.
I replace the 510 transistor. Sill no output. The current does jump up to
over 1 amp when I switch to transmit.
|
I did not activate the attenuator or the IPO.? I wanted it to be as apples to apples as possible. ? I can also turn down the RF gain and run up the AF gain for some of those buried signals. ? The noise is definitely there, ?but the 817 has a few extra tools to deal with it. ? I'm sure the larger speaker I'm using on the BITX helps too.?
Kent W9WB?
On Jan 1, 2017 8:43 PM, " parkerp@... [BITX20]" < BITX20@...> wrote:
?
Bitx definitely the best sounding of the lot.?
Excessive gain + AGC can create that commercial gear 'canned audio' sound that builders enjoy freedom from. ? I'm a big fan of the FT817 but yours sounded overloaded. Did you try the attenuator and IPO??
73, Peter VK3YE
|
Bitx definitely the best sounding of the lot.?
Excessive gain + AGC can create that commercial gear 'canned audio' sound that builders enjoy freedom from. ? I'm a big fan of the FT817 but yours sounded overloaded. Did you try the attenuator and IPO??
73, Peter VK3YE
|
Re: It stopped transmitting
If the 510 gets hot, I'd check for shorts in the coils of the low pass filter or the antenna connector.?
If you are intending to replace the relay, you could pull it out and short the connectors for transmit. If the fault IS the relay, then you would get an output. If you still have low output, then chances are the fault is elsewhere?
73 Dave G4UFS
toggle quoted message
Show quoted text
On 1 Jan 2017, at 14:34, Bill Kittilson bill@... [BITX20] < BITX20@...> wrote:
?
I can hear the bitx on a near by receiver. ?The coils look fine. The 510 gets hot on transmit. ?I hear the relay but it don't sound quite right. I order the replacement relays. I hope it's the simple. ?Thanks. I'll update you when i get the replacement. ?
Thanks.?
?
Bill,
Check L6 and L7 and see if it is making contact with the solder on the board.
Check the relay K2, I seriously suspect that it could be faulty. Take the output from K2 pin 16 and ground to a (bnc) connector and check the TX out there with a power meter. If there is normal output then relay is suspect.. or not operating. When you
press PTT the relay should click, you should feel that with your finger. I have seen a lot of similar relays fail in my service
experience.
Cood luck and Happy new year!
Raj vu2zap
At 31/12/2016, Bill Kittilson bill@... [BITX20] wrote:
>
>
>I managed to kill my bitx40. It was working great until I decided to tune up the big rig. I can still receive. No power at all on transmit. I replace the 510 transistor. Sill no output. The current does jump up to over 1 amp when I switch to transmit.
>
>Any idea what to look at next?
|
Kent,
I think your BitX40 had the best sounding audio of them all, the 450 next, and I was astounded at how noisy the 817s receiver was, and to think I always wanted one of those, not anymore. Joel? KB6QVI
toggle quoted message
Show quoted text
On Jan 1, 2017, at 3:58 PM, Kent Vanderploeg kvanderploeg@... [BITX20] < BITX20@...> wrote:
?
After my initial troubles with a broken L2, the BITX40 is hearing well and making some surprising contacts. Here's a little comparison video of the received audio from the BITX, the FT-817, and the FT-450D.
Kent W9WB?
|
After my initial troubles with a broken L2, the BITX40 is hearing well and making some surprising contacts. Here's a little comparison video of the received audio from the BITX, the FT-817, and the FT-450D.
Kent W9WB?
|
Ideally, with the stock kit
Ideally with the stock lm386 & with an 8 ohm loudspeaker, for good intelegebility, how many watts would be best? Also, though a mic element is already supplied, what would be the ideal impedance for a microphone element?? Tnx Jerry AA1OF/6
|
Got it, thank you. I couldn't find the pot wiring on the schematic showing the wiper.
73
Tom
|
Re: It stopped transmitting
Sometimes, I use IC base for those relays...
'Repair & Reuse or Recycle E-Waste'
|
Joel Caulkins/N6ALT
Raj vu2zap