开云体育

Somewhere, in the loft of the garage, above the shack, rests my old HP-65. I lived on ramen and cheap hamburgers for several months,
scrimping and saving for that freshman EE major's dream, complete with mag stripe program packs and printer, for $750.00 (1976 USD).
I'm posting this from a $35 Raspberry Pi, that's also running the Arduino IDE as I tweak my uBitx. Guess being an early adopter has it's pitfalls. ;>}.
73's DE
KD0KSP
Ted

Been using HIFI Berry + and RTC for a few years now for Audio Playback just thought others might be interested since they now have DSP and ADC versions. The only other cards I've seen where either low bit rate or audio only. Plus they ship quick and build quality so far great, have to admit I've seen a few other High End cards out there but way too expensive. Just wish they included RTC Chip on ADC Card.

Scott,

The TP's are for RF and not for DC voltages.

Raj

Pat

Just a few things. I would do some partial assembly of the raduino, main board etc to get a feel for things. Many in qrp community like bnc, of course idea is to do it the way you want it. For some folk in the world, that ptt and microphone element get them on the air. Yes normally open ptt.

I suggest wiring up both headphone and speaker. You may find audio output lacking to drive a speaker. Some folk use an external amplified speaker, or add an internal audio amplifier.

I suggest you visit some websites from around the world that describe bitx assembly.

Curt

I opted for the Audio injector Ultra sound card instead.?

Dennis,
Sounds like you have an ubitx. Please verify your kit model. My Bitx40 doesn't have these extra parts but my ubitx does. Big difference in wire up instructions.

Paul
KL7FLR

Just to add I received my Smarti PI Touch case for original PI Touchscreen I bought few years back and haven’t used because it was flemzy and awkward. This new case not only mounts screen with PI but has an optional back cover with room to mount your project in the case. Here is the website?https://smarticase.com/ ?

They are also on sale so bought two more. I will be using on with a SDR I’m building . For those who like the PI you should check it out.

Thanks,

Jim


Im not affiliated with this place either.

Hi
This spreadsheet of expected voltages is useful, but is there a table of expected voltages for the actual test point numbers?? TP1, TP2, etc.? This would be even more?useful as, on the v4 board, these TP locations are stenciled in and easy to find and get at with a probe.? The legs of teeny tiny SMD transistors are harder to target.?
73, Scott VO1DR

Thanks Jack.

My BITX40 v 4c kit has three resistors and a diode loose in the package of connectors and other parts. I have not been able to find any instructions as to where these resistors should be installed. I did see a partial schematic someplace that indicated a diode across the power inputs to prevent against improper polarity, but no where have I found any instructions to actually make that installation or how to install the resistors. I’ve reviewed everything in the BITX40 folder of the Wiki files as well as other assembly info I could find both on this site and the hfsignals site. Could somebody steer me in the right direction? I probably missed it somewhere. Getting old and feeble minded I guess.
Thanks
Sodypop@...

Jim,

Why a separate AM detector? When the reference oscillator is calibrated then you just tune to the carrier frequency and it is zero beat. I've been listening to broadcast on the BITX since I first went digital with them. It works better than the normal AM detector since the carrier isn't necessary. No distortion. Exalted carrier.
Biggest issue is the narrow filter band pass. But it's good enough for my ears.
73,
Don

Jim,

Would you kindly share your findings.

73, Bob GM4CID

Hello,

A lot of folks here not only have ubitx, bitx, SDR, etc.... this post may be of use for some.

If you have Raspberry PI and use for SDR or other things a company now sells a 24bit ADC / DAC for the PI. They also sell a DSP Card as well, don’t know if you can use and make for radio use, but if interested check out the??website.

I’ve ordered two of the ADC cards for audio use, but 24 bits is even more than the Teensy Audio Card, and with PI you could make all kinds of things, even stand alone SDR.

Just for info, not affiliated with anyone.

jim