Search found 45 matches

by John
26 Sep 2022, 05:02
Forum: Troubleshooting
Topic: Classic bands: No output on 20/10m
Replies: 6
Views: 244

Re: Classic bands: No output on 20/10m

wb9oqb,
Well done. - ad0wo
by John
07 Sep 2022, 00:09
Forum: Troubleshooting
Topic: Enabling VOX causes bad RX
Replies: 11
Views: 324

Re: Enabling VOX causes bad RX

You haven't mentioned if the rig works properly on CW, or on SSB, or AM, or FM each with or without VOX enabled, i.e. other modes that use the Mic inputs to the processor. That would tell us more about the specific nature of the problem. Either way, my guess is that it's a problem with the microcont...
by John
27 Aug 2022, 21:24
Forum: Troubleshooting
Topic: (tr)uSDX power, efficiency and filter optimisation
Replies: 174
Views: 24262

Re: (tr)uSDX power, efficiency and filter optimisation

To the best of my knowledge these parts in these circuits always put out more power at the bottom of the band and then taper off as you go higher in frequency. If you only use 1 part of a given band you can tune the power output for just that frequency range. But I tune them for the bottom of each b...
by John
17 Aug 2022, 16:07
Forum: Troubleshooting
Topic: (tr)uSDX power, efficiency and filter optimisation
Replies: 174
Views: 24262

Re: (tr)uSDX power, efficiency and filter optimisation

I see you are not using the pin header connection to the RF signal pin recommended in Manuel's video. Nor can the point where the connection is actually made be identified in the photo. It would be best to verify that your connection is made to that same trace in the circuit. Unfortunately, I find t...
by John
14 Aug 2022, 08:48
Forum: Troubleshooting
Topic: (tr)uSDX power, efficiency and filter optimisation
Replies: 174
Views: 24262

Re: (tr)uSDX power, efficiency and filter optimisation

You might want to take a photo that shows us how everything is cabled up, (coax cable,) along with the process you are going through to get those readings. Also a photo that shows the RF board up close.
John
*******
by John
12 Aug 2022, 01:44
Forum: Troubleshooting
Topic: a problem when i connected (tr)usdx first time to battery
Replies: 10
Views: 619

Re: a problem when i connected (tr)usdx first time to battery

Tantalum electrolytic and aluminum electrolytic capacitors when connected backwards will usually work for a while if you are operating on low voltages relative to the rated voltage of the caps. That's probably why it worked on the 5 Volt USB supply. But once you hit it with 12 Volts the dielectric l...
by John
12 Aug 2022, 01:35
Forum: Troubleshooting
Topic: Transmits all modes except CW.
Replies: 15
Views: 853

Re: Transmits all modes except CW.

Have fun Bill. I would have enjoyed troubleshooting that rig, as it's a very interesting problem. But I haven't even had time to finish tuning my (tr)uSDX inductors. Besides which I'm sitting here with 2 QDX kits I haven't even started on. But please let us know what you find out, since it is indeed...
by John
24 Jul 2022, 12:41
Forum: Troubleshooting
Topic: SWR Meter affected by Audio cabling?
Replies: 2
Views: 202

Re: SWR Meter affected by Audio cabling?

That sounds an awful lot like RF coming down the outside of your coax due to an unbalanced coax cable running to a balanced antenna. That can cause all sorts of glitches and wandering readings to occur.
by John
24 Jul 2022, 12:35
Forum: Troubleshooting
Topic: Transmits all modes except CW.
Replies: 15
Views: 853

Re: Transmits all modes except CW.

Hi. I see in your original post you state " but for some reason tonight it won't transmit on CW using the PTT button." Your comments regarding this very unusual problem seem to narrow down the possible source of the problem to the keying firmware, since essentially all of the hardware invo...
by John
13 Jul 2022, 18:51
Forum: General Information
Topic: Display noise
Replies: 8
Views: 560

Re: Display noise

Is there any reason not to simply add an on/off switch for the display to shut it off when not needed in order to stop noise? It would also save power. I'm mounting my rig in a somewhat larger metal box, so a switch for the display would be no big deal. I was already planning on it as an energy-savi...
by John
13 Jul 2022, 18:37
Forum: General Information
Topic: Add On Features 2023?
Replies: 2
Views: 366

Re: Add On Features 2023?

I wouldn't say ham radio is completely superior communication to cellphones. I would say it is very different, and far superior during times of emergency. Cellphones require every part of large, sophisticated networks to be functioning properly in order for them to work at all. When the cell-tower i...
by John
11 Jul 2022, 15:59
Forum: Troubleshooting
Topic: Main board failure
Replies: 5
Views: 436

Re: Main board failure

I use an infrared thermometer gun to check the temperatures of devices in my circuits. It's not as quick or convenient as an IR camera for finding shorts and heat problems, but it works well and provides a precise value for the temperature.
by John
08 Jul 2022, 16:50
Forum: Troubleshooting
Topic: SSB TX sounds way off frequency
Replies: 16
Views: 871

Re: SSB TX sounds way off frequency

I'm no expert, but if you've tuned around and it still sounds "tinny and robotic" and unlike other SSB signals, then I would suspect some modulation problem other than it being off frequency. Have you tried an external microphone?
by John
08 Jul 2022, 03:37
Forum: Troubleshooting
Topic: Experience with Amazon kit and troubleshooting
Replies: 7
Views: 587

Re: Experience with Amazon kit and troubleshooting

Fun little rigs, aren't they? And amazing performance for the size and money. Firmware definitely rules. Cores inductance and losses do vary, perhaps by as much as 5 or 10%, not only from different suppliers, but even between batches from the same supplier. {"40m is still low. Transmitting belo...
by John
06 Jul 2022, 07:54
Forum: Troubleshooting
Topic: 0W output power on all bands after removing a turn from L31
Replies: 4
Views: 381

Re: 0W output power on all bands after removing a turn from L31

It's possible that when you removed 1 turn from the coil you did something that changed the circuit the FET's were driving through and a high VSWR blew up the FET's. Perhaps there was still insulation on the wire of the toroid, or a small solder bridge occurred when you removed the wire from the tor...
by John
06 Jul 2022, 07:28
Forum: Troubleshooting
Topic: Problem connecting to external PA
Replies: 24
Views: 1312

Re: Problem connecting to external PA

You have said it "will not operate" with the mod, but you didn't mention what was actually happening. Does the amp do nothing when you press TRANSMIT? Does it key the transmitter the moment you push in the plug? Have you observed the voltage on the (tr)uSDX transmitter keying signal going ...
by John
04 Jul 2022, 22:31
Forum: Troubleshooting
Topic: Problem connecting to external PA
Replies: 24
Views: 1312

Re: Problem connecting to external PA

"Unfortunately, this does not happen – DESPITE having the correct wiring on the connector(s)." The question is, "What is the correct wiring on the connector?" All the cable for your amplifier's transmit function needs to do is short together. Polarity doesn't matter. It will work...
by John
25 Jun 2022, 20:19
Forum: General Information
Topic: Sticky: Post (tr)uSDX questions for the developers (Manuel DL2MAN and Guido PE1NNZ) in here
Replies: 136
Views: 25875

Re: Sticky: Post (tr)uSDX questions for the developers (Manuel DL2MAN and Guido PE1NNZ) in here

I saw a posting in the forum about an upgraded schematic for the radios having been created, and since when I was troubleshooting the rig after assembly I found I had some trouble reading the one that's presently available I would like to know if the licensing problems have been resolved so I can ge...
by John
29 May 2022, 10:43
Forum: Troubleshooting
Topic: Dropped a clanger
Replies: 2
Views: 392

Re: Dropped a clanger

Hi Martin. From context, I'm guessing that "dropped a clanger" means you did something that wasn't good. I took a quick look at the Gerber trace files, and if you pulled the pad off the bottom of the board it doesn't much matter just as long as you can top-solder the coil leads, since, (if...
by John
29 May 2022, 08:48
Forum: General Information
Topic: (tr)uSDX - Alternative Band Setups available
Replies: 87
Views: 13936

Re: (tr)uSDX - Alternative Band Setups available

AC9YY, to the best of my understanding, the bias level is not a power adjustment, and shouldn't be used as such. Yes, it does have an affect on the absolute power output, but that's a side-effect, and not typically a good thing since the bias voltage is an offset used to set the point where the FET'...
by John
20 May 2022, 06:15
Forum: Troubleshooting
Topic: PA Fets blown by connecting USB?
Replies: 13
Views: 996

Re: PA Fets blown by connecting USB?

I can easily see people hooking up their 12V and USB cables for CAT operation without first attaching an antenna or dummy load, and not realizing that the CAT software drivers may be pulsing the transmitter before the system is all set for 'transmit' modes, so that could be it. 'Random' power-up and...
by John
20 May 2022, 05:42
Forum: Troubleshooting
Topic: First power up and getting a large number in the display?
Replies: 6
Views: 454

Re: First power up and getting a large number in the display?

I'm not exactly sure how these things work, but I think you might want to delete your serial number from your post so it doesn't get spread around and misused.
by John
19 May 2022, 00:34
Forum: Troubleshooting
Topic: PA Fets blown by connecting USB?
Replies: 13
Views: 996

Re: PA Fets blown by connecting USB?

I have a couple of ideas, based simply on my R&D and repair experience, since I've not yet hooked up both a PC and a 12V supply to my (tr)uSDX, and have run into no problems as yet. But first, 2 caveats: 1.) I'm not an EE. I don't even have an Associates degree. 2.) I have a good deal of trouble...
by John
17 May 2022, 19:49
Forum: Troubleshooting
Topic: (tr)uSDX power, efficiency and filter optimisation
Replies: 174
Views: 24262

Re: (tr)uSDX power, efficiency and filter optimisation

A class E amplifier properly tuned using good components is inherently more efficient than a class AB amplifier. Obviously these rigs in kit form have not been optimally tuned, nor have the manufactured units, because optimal class E tuning on 5 bands takes time that can't possibly be put into a $10...
by John
11 May 2022, 03:10
Forum: Troubleshooting
Topic: band 6M and 4M
Replies: 1
Views: 318

Re: band 6M and 4M

If I understand it correctly, the (tr)uSDX has been designed to have a standard hardware and firmware format so it can be built inexpensively, and supported here by the original designers and there won't be an assortment of weird variant, undocumented Chinese knockoffs produced by unscrupulous vendo...