Hammond transparent blue box. Advantage: no display window is required.

Would be nice if this can work with a LO of 9.667MHz to receive 2m band
Or is a substantially reduced sensitivity to be expected?

Erik

The detector will receive on all odd multiples of the LO.
However, as it is a sampling detector it means samples are missed.
Even at 3 times the LO sensitivity is down by almost 9dB.

73 Alan G4ZFQ

Thank you.? I'm working on your suggestions.? I appreciate the help, and I'm going to look closely at all of them.??

When experimenting with BPF I noticed the receiver module will receive a station transmitting at 15.4MHz when tuned to an LO of 1.03MHz. Of course only when using a well tuned BPF to get rid of the noise or transmissions at lower frequencies and at a 20 dB lower level. Seems to be the 15th harmonic. Its seems also possible to receive at the 5th harmonic of the LO
Is this to be expected?
Could that also work on higher frequencies? I did not yet try BPF above 15MHz.
Would be nice if this can work with a LO of 9.667MHz to receive 2m band
Or is a substantially reduced sensitivity to be expected?
I will give it a try anyway
--
Erik@Home

开云体育

Tony, N0PBA, no, you need to lower the value of C21 and C22 so paralleling additional caps with the originals will not get you there.? I also suspect that DC leakage that are a characteristic of electrolytic capacitors may be playing a part here as well, so the original C21 and C22 capacitors need to go.

73,

Robert, WA2T

If you perform a RESET and follow Hans directions in DIAGNOSTIC mode there is a procedure to follow to fault find this.

73 Ken G4APB

In answer to your original question, manual entry of the maidenhead locator is for when you DON'T have a GPS connected. Once you add the GPS and select it in the menu it will automatically update/overwrite whatever you entered (or didn't). Only the 4 figure locator is sent in WSPR mode unless you choose the two pass, 6 figure option.?

73 Ken G4APB

Hi Jim

> The Extended byte used by your Arduino programmer is inverted as compared to my
> universal programmer, so my 0xFC matches your 0x04?

Just to be clear: the extended byte is NOT inverted! In fact, the actual situation is that the unused upper 5 bits of it are defaulted to 1 in your programmer (and mine). This is an unfortunate point of inconsistency between AVR programmers, which can lead to some unnecessary confusion. The ATmega328 uses only the three least significant bits of the Extended byte. The correct setting for the QRP Labs firmware is 0x04 or 0xFC, these are the same... In Binary:
0bXXXXX100?
(where the X indicate that the chip doesn't care whether it's a 1 or a 0).?
The only difference between programmers is the way they read back the un-used bits; some read them back as 1, some read them back as 0. If you program the fuses as 0xFC i.e. 0b11111100 or as 0x04 i.e. 0b00000100 it makes absolutely no difference to the ATmega328 chip. But it DOES make a difference when you read back the fuses in your programmer during the verification step! If the programmer reads back 1's and you said 0x04, then you get a complaint; if it reads back 0's and you said 0xFC then you get a complaint. So... the moral of the story is to check the error message carefully and bear in mind all of the above :-)

So for clarification, these are the correct fuse settings for all current QRP Labs products using the ATmega328:

Low: 0xF7
High: 0xD1
Ext: 0xFC or equivalently, 0x04 (see above)

You may also see the High fuse set to 0xD9, this just means that the "preserve EEPROM contents through chip erase" fuse has not been set. Then when you erase the chip to flash the firmware, it will also wipe out the EEPROM contents. It is much better to preserve the EEPROM contents (and in the QCX, it is NECESSARY). In the U3S etc it avoids re-doing all the configuration settings. In any case where the new updated firmware has a different EEPROM layout to the former firmware version you had, then the firmware will automatically re-write the EEPROM to factory defaults. QCX chips and others now supplied have High 0xD1, which means the EEPROM contents ARE preserved. So I recommend this setting 0xD1 for everyone.?

The above applies whether the chip supplied (or the blank that you procured) is an ATmega328 or an ATmega328P. For the purposes of QRP Labs kits these two types of chip are both suitable and equivalent. We supply one or the other type depending just on availability and price. The suffix PU e.g. ATmega328-PU just indicates the 28-pin DIP carrier.?

A reminder of QRP Labs policy on firmware for all kits:

• Firmware upgrades on any product are free for life; the .hex files are published here in the group files section for you to upgrade your chip
• If you don't want to or can't upgrade your own chip, then you can buy the physical upgrade chip for any QRP Labs product here in the shop:?
• If you feel sufficiently upset or aggrieved about some kind of malodorous bug which has significantly perturbed your state of happiness, you can email me off-list and I will arrange a free upgrade chip to be sent to you
• In general, Source code is not available (not open source)
• Using QRP Labs firmware in your own one-off homebrew projects is Ok, but using QRP Labs firmware in any other commercial or quantity-produced kits or products is absolutely prohibited and severely un-cool!!

73 Hans G0UPL
http://qrp-labs.com

Thank you Robert. I just bought 100 ceramic 0.1 mfd caps Digikey so I’d have extras, so that’s perfect. I think I left my stock at home and I’m on the road again, but I will replace them as soon as I get back.

73,

Charles - NK8O

GPS still works. Unit still pulling same idle amps.?

My display went dark? it has the much talked about single row of squares. The U3S was working for days. I've searched the topics. Can't find where to start.?

Just got the case kit in the mail today.? It looks great!? My question: What connector will fit in the GPS cutout?? It's too small for a 9 pin DIN.? I'd like to be able to use the QLG1 when the QCX is in the shack and beaconing WSPR.? Being able to hook up/unhook the QLG1 is very appealing. ?
Thanks in advance,
Pat W0BM

开云体育

I have just completed my QCX 40, and have been able to make a few contacts with it.? I had to turn down the volume on the side tone, and when I did I encountered this loud clicking problem.? I too like to work QSK, so do not want to go semi if it can be avoided.? I came to this forum for some research, and, Lo and Behold! I found this very topic of discussion.

My question is: can I parallel another cap with C21 and C22 to get the needed value, or do I need to pull them both and replace them.? To me this is a messy chore as I am not as adroit as I need to be sometimes.? And the final value needs to be 0.1uf, correct?

Thanks for help and for all the great info on this forum!

Tony, N0BPA

开云体育

Decided to buy a Rasberry Pi and try to reflash the RF module. ?While I have some experience with the Arduino I have none with the Raspberry Pi. Followed Hans’ excellent directions and worked perfectly! I now have a fully functional GPS. ?I also now have a nice Raspberry Pi to experiment with.?

To Charles, NK8O, the .1 uF caps are non-polarized, ceramic or otherwise, so not electrolytics.

73,

Robert, WA2T