Heard N6ORS but guess he couldn't hear me I think he was running 60W. He was chatting with Mike NX2U but I couldn't hear him...Otherwise quiet.

Think I got to get on in the 3PM slot...seems like I had a lot better luck in that time frame.

Also,? RV1 Drive level has no effect on the feedback issues, happens just the same at 5W as at 15W...

Thanks Richie...that was probably you I heard earlier right in my noise floor. Looking forward to radio contact. Too many chores today to spend a lot of time on radio - i know - poor planning on my part.?
FYI I listen on 7.277 most days and night if in the shack or shop - always looking for qso's other than just sundays. Give a call and let's make some NOISE !

Well, i have dont my mods and powered up. Results are mixed:
Here are the mods.
RD16 replace IRF510.
New output transformer 1:4 BN43-3321 with a 330pf cap on input.
feed back resistors. from 22ohm to 1 K ohm
piggy backed R87 and R88 with 220pf capacitor.
RV1 full drive.

So results.
80M - 20W + ( blew my 2 Amp fuse)
40M - 18W - Seems stable.
30M - 17W BUT I get BAD feedback/ oscillation by just going PPT with no voice. The watt meter goes up to 18W!
20M - 15W? -? Same feedback issue
15M -? Same feedback issue.
10M -? Same feedback issue.

I have been thinking ans looking at other RD16 schematics, in alot of cases they dont use the feedback on the finals?
Also could this issue be cuase in the driver stage?

THanks guys, I am in over my head here....

73
10M - Same feedback issue

Was able to speak briefly with NX2U and then the band dropped out. Made first contact with my ICOM-7300 and then set up the uBITX.? Had a few words with him and then nothing.? Using an LDG QRP autotuner and a Timewave DSP9+ with the uBITX

--Neil, W2NDG

7:45 local time in EST - where is everybody hanging out? Not hearing anything except my neighbours washing machine and I don't speak "machine language" .

Hearing NX2U off an on. Called, but no answer!
--
John - WA2FZW

On my latest BITX40 I snuggled the display up next to the edge of the case close enough to enable easy access through the side of the cabinet with just a minuscule aperture. Hardly visible. On the uBITX I used a very short adapter cable (about a foot long) and brought it to the back panel. A short extension cable then connects it to the computer for re-flashing the Nano. It works well and I can avoid opening the case every time that I feel like changing the software (which is frequent). Two caveats: Keep the cables short, and use good cables. Otherwise it is wonderfully advantageous. -Don

Was able to work Nx2U and one other operator. Hearing carrier from 7.25mhz.? 7.29mhz is better

Jerry,

Diddling with the BFO to make it a clarifier is not good. I agree it is a bad idea today. It worked back in the 50's and 60's because there wasn't much of any other choice and the filters weren't as sharp as they are today. It's why on the old RME 4350 it was always recommended to reset the bfo dial to zero. If you didn't your transmitted frequency wouldn't necessarily jive with your received frequency. Of course back then, a 1kc resolution was considered good and most people had separate receivers and transmitters so it didn't matter as much.

If you want a true clarifier it should be done with the vfo frequency and the offset from the transmitted carrier frequency should be indicated somewhere on the display.

Based on the message Allard left earlier, he *did* implement a true PBT by adjusting the vfo and the bfo so the suppressed carrier frequency is not changed but the relationship to the SSB filter changes. Again, it just goes to show how advanced this little rig actually is!

I think we finally have everything defined correctly. You and I agree.

The design of this radio is impressive. I've had several home built receivers where switching between usb and lsb involved changing the if frequency to move from one side of the filter to the other. Since most simple filters are asymmetric (the slope on the high side and the low side are not the same, the two never sounded quite the same going from usb to lsb.

This design seems to eliminate this problem in the if chain so the bfo remains constant and the filter response is the same on both usb and lsb.

Nice.

tim ab0wr

I'm looking for ideas on what others are doing regarding mounting a micro USB connector to the ubitx case.? I'm finishing the case customization and would like to be able to connect the raduino USB to my laptop (or a raspberry pi) for CAT and digital communication.? It would also be used for upgrading the firmware and debugging with the IDE.? I would like to be able to do this without having to open the case.? I haven't seen this anywhere on the blog yet (but I may have missed it).? The panel mount USB micro connectors I've see so far are pretty long (over a foot in length).? I may have to cut s cable and recrimp for a solution.? I'm curious what others have done.? A picture of my case is in another post:? /g/BITX20/topic/14362664? Thanks for any help you could give.
Tom
AB7WT

Marco

I bought the MPSH10's about 5-6years ago. Perhaps less of an issue with fakes then.

glenn

Hi John

Totally out of the box uBITX, (ie no mods)? I checked power out in CW mode

120118

Checked using CW key at 12.5v dc in. VR1 at ~60% anti-clockwise. (factory setting)

·?????

·???????? 80M = 12w

·???????? 40M = 8.5W

·???????? 20M = 4.8W

·???????? 10M = 1.2W

Turning up VR1 to full rotation.

80M = 15w
40M = 12w
20M = 7.8w
10M = 2w

glenn

Also,? there is a site and you may have seen it because the owner of the site, Don, ND6T is active here. What he does is put a little code in the Raduino and tell it to go directly to 25 mhz. He had to use code because I believe he wrote this piece before raduino was installed in a uBitx, it was I believe BITX40. So, you measure the raduino when its at 25, noting the actual freq. Then you change the code with the L at the end, I believe similar to this line???? if (prev_freq <= 10000000l && frequency > 10000000l)? (but uses 25000l) until the 25mhz sig is actually on frequency. However, actually having a knob to adjust receiver freqs as your discussing in the other thread on IF Shift, would be great.? ND6Ts,,, Its here ...?

Thanks to all for the great input!? Now, I've got some good direction on what to do next.? Very helpful!

Bert, I got the tuning knob idea from a vintage Swan 270B I have torn apart for repair.? I found a place on ebay which had new knobs:

??????? Swan Fluted Tuning Knob for Amplifiers & Tuners
???????

I actually made a mistake on this part.? They have 2 models: one with a white marker on the dial (above) and one with no markings on it.? The seller was great and corrected the order for me before shipment when I reached out to him.? Look for ke9pq on ebay.? I think the actual part he corrected for me was:? "Swan Fluted VFO Tuning Knob with 2" Skirt & Alum Inlay".? Shipping was free and super fast (only took a few days).

Tom
AB7WT

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开云体育

Hi Marty:

If available I will take it. Paypal to ????

Tim

WB7UVH

Hello Glen,

Very interesting. Do you have measurements of you final's power across the bands by any chance?

All the best,

73, John? (vk2eta)