Yes it is the other half of the U20 comparator IC. You could swap the IC out too. Your idea of tying the input to 5V is a good way to go.
Search found 56 matches
- Tue Apr 28, 2020 11:58 pm
- Forum: FM Radio
- Topic: Digit or Digit-CD full manuals
- Replies: 28
- Views: 1268
From the schematics that were linked earlier, have a look at page 19. That shows the circuit for the RF mute input. You could try checking the components connected to that. Particularly R3, R30, CR1, C5. Also monitor the voltages around U20 and at TP4 during the good and fault conditions. The fault ...
- Fri Feb 28, 2020 12:26 am
- Forum: Production Studios
- Topic: Small and robust sound card. Recommendation?
- Replies: 2
- Views: 1192
For a card, have a look at the Sonifex PC-AD2. It is not cheap at around $700, but is fully balanced. Or for a USB device, the Yellowtec PUC2 is good.
- Mon Jan 06, 2020 1:54 am
- Forum: FM Radio
- Topic: Smart AC Power Circuit Breaker with Web Control?
- Replies: 18
- Views: 784
The old panel box is about 40 years old. I would never want a circuit breaker that I can't reset in person. If something causes a trip, you're not sure, hit "reset", and it comes back, you could be looking at replacing the panel with the rest of the building that burned down. For the nuisance for a...
As far as wind turbines go, the support structure is steel and represents a permanent reflector, but as Deep Thought suggests, that is probably a minimal problem if many wavelengths away. Of course, FM is not analog TV, but I know of one instance where a tower caused a permanent reflection (ghost) ...
Keep in mind that a lot of the older Marti and other STL transmitters use RF modules that are unobtainium. Often another available module will work at lower power but I haven't had real good luck long term with those conversions. Additionally, some of the Marti receivers have VCO (IIRC) modules tha...
- Tue Aug 27, 2019 9:17 am
- Forum: FM Radio
- Topic: Optimod 2300 Tally Output to Sine RFC-1/B
- Replies: 3
- Views: 482
The NPN output transistor in the Optimod has its emitter connected to ground (pin 1). So you can use the collector which is the actual output to control anything so long as you stay within the current and voltage rating of the transistor. You can use a resistive potential divider so that you can pul...
If the filter is not inline, then it could have been removed because it makes the VSWR problem worse. That does not necessarily mean the filter is not correctly tuned as changing the length of the feeder will affect the VSWR shown at the transmitter. If you are getting enough RF from the other trans...
You would certainly want all transmitters any where near that system to be off before you connect your spec analyser to the system. Test with plenty of attenuators first. Without knowing some details of the antennas, it is hard to comment further. You might have an issue that is not down to tuning o...
- Thu Aug 01, 2019 2:26 pm
- Forum: Radio Studio Engineering
- Topic: Arrakis ARC-10 USB Noise
- Replies: 9
- Views: 1615
Finding a decent professional USB audio interface is not easy. One I have used with good results is the Yellowtec PUC2. It is 2x USB powered, so does not achieve the high levels of the Henry box, but a good choice if you want something USB powered. Like the Henry, it does not have any knobs or butto...
Personally, I am not a fan of the FX-50. You could add the GatesAir Flexiva Compact which has a 50W version to your list. Not cheap, but very good. You might be lucky and find something used.
I have seen all sorts of tools used and I have come to the conclusion that so long as you get the end square and clean and clear out the dust it does not matter how you do it. A band saw sounds reasonable to me. I hope the install goes well, the FAX is a good transmitter in my experience.