Search found 45 matches

by DaveSt
Thu Aug 01, 2019 2:26 pm
Forum: Radio Studio Engineering
Topic: Arrakis ARC-10 USB Noise
Replies: 9
Views: 383

Re: Arrakis ARC-10 USB Noise

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...
by DaveSt
Wed Jul 17, 2019 11:34 pm
Forum: FM Radio
Topic: Exciter shopping
Replies: 9
Views: 311

Re: Exciter shopping

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.
by DaveSt
Tue Jul 16, 2019 11:24 pm
Forum: Ask the Engineers
Topic: Cutting Hard Line
Replies: 12
Views: 324

Re: Cutting Hard Line

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.
by DaveSt
Sat Jul 13, 2019 2:39 am
Forum: FM Radio
Topic: Harris Z FM FET replacement
Replies: 7
Views: 372

Re: Harris Z FM FET replacement

There is some calibration needed, not least of which is the bias. It is better to send it back rather than risk killing expensive MOSFETs.
by DaveSt
Wed Jul 03, 2019 11:49 pm
Forum: Everything else
Topic: Which Android App to Record Interview directly on phone?
Replies: 2
Views: 170

Re: Which Android App to Record Interview directly on phone?

The Tieline Report-IT app can be used for recording. Obviously they would like you to buy one of their codecs for the live side, but the recording bit is free as I recall. http://tieline.com/products/G5/Report-IT
by DaveSt
Wed Jul 03, 2019 3:13 pm
Forum: Everything else
Topic: What's with all the spam lately?
Replies: 6
Views: 125

Re: What's with all the spam lately?

Probably the moderator(s) are busy earning money in their day job rather than sitting in front of a computer all day to catch the spam as it appears. To me the amount of spam here is not bad and is easily ignored as it is so obvious. It usually gets killed within a day or so anyway.
by DaveSt
Mon Jul 01, 2019 9:23 am
Forum: FM Radio
Topic: 75 uSec Pre-Emphasis Graph
Replies: 11
Views: 430

Re: 75 uSec Pre-Emphasis Graph

There are some very simple browser based circuit simulators. For example https://www.circuitlab.com/ . For pre-emphasis you can do a parallel RC combination into the non inverting input of an op-amp. If you have the circuit of the pre-emphasis part of whatever box you have, you can simulate it exact...
by DaveSt
Thu Jun 06, 2019 5:35 am
Forum: FM Radio
Topic: Changing Frequency Of Belar RFA-1 FM RF Amplifier
Replies: 6
Views: 337

Re: Changing Frequency Of Belar RFA-1 FM RF Amplifier

I would have thought the front end and LO coils would have the range for the whole of the FM band. As Deep Thought said, it is a simple circuit and retuning should not be a challenge for any one with a little experience.
by DaveSt
Mon Apr 15, 2019 9:53 am
Forum: Ask the Engineers
Topic: Audio dropouts on Yankees game broadcasts
Replies: 34
Views: 1372

Re: Audio dropouts on Yankees game broadcasts

13dB is very good, so no problem there. $5000 for one of these boxes sounds like more than double what it should be, unless it is gold plated. I am going to guess the carrier is DVB-S QPSK 3/4. So you could put just about any other receiver on that with a splitter, even a domestic receiver and see i...
by DaveSt
Mon Apr 15, 2019 1:22 am
Forum: Ask the Engineers
Topic: Audio dropouts on Yankees game broadcasts
Replies: 34
Views: 1372

Re: Audio dropouts on Yankees game broadcasts

It looks like your downlink frequency is 4029MHz based on the IF frequency shown by your receiver. That is good as interference problems are more of a problem at the lower C-band. The filter on the feed itself may be from someone like MFC. These filters became very popular for getting rid of interfe...
by DaveSt
Fri Apr 05, 2019 3:08 am
Forum: STL Engineering
Topic: RDS options
Replies: 15
Views: 681

Re: RDS options

There is a document that covers this from the RDS Forum. It is old, but still relevant: http://www.rds.org.uk/2010/pdf/R09_048_6_no%20pw_57.pdf . The important bits are highlighted on page 4. Page 40 of the NRSC guidelines also has some information on page 40: https://www.nrscstandards.org/standards...
by DaveSt
Thu Apr 04, 2019 1:52 pm
Forum: STL Engineering
Topic: RDS options
Replies: 15
Views: 681

Re: RDS options

That is absolutely true... However, I don't really see any reason that a line of ad text rotating onto the radio display every few minutes would alienate listeners. Well other than DT... It's not like they blast off at double volume in the middle of your favorite tune the way audio commercials do. ...
by DaveSt
Mon Apr 01, 2019 1:30 pm
Forum: STL Engineering
Topic: RDS options
Replies: 15
Views: 681

Re: RDS options

If you just need to get RS232 data over an IP connection, then Lantronix make some good boxes for that. The UDS1100 for example.
by DaveSt
Fri Feb 22, 2019 11:48 pm
Forum: TV Engineering
Topic: Adding Genlock
Replies: 39
Views: 1054

Re: Adding Genlock

I think you are correct. Just lock up all the sources and the Tricaster.
by DaveSt
Fri Feb 15, 2019 2:21 am
Forum: FM Radio
Topic: Optimod 2200
Replies: 6
Views: 526

Re: Optimod 2200

The A/D and D/A converters can cause problems on these older Orban products. Usually they just die, but what you describe is possible. You can find them on Ebay or I think Orban will still repair these units. The 2200's are still well worth repairing. Personally I think they were the best processor ...