Search found 56 matches

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: 253

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: 246

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: 697

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: 495

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: 1892

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: 1892

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: 1189

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: 1189

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: 1189

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: 1571

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: 755

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 ...
by DaveSt
Tue Feb 12, 2019 10:20 am
Forum: Ask the Engineers
Topic: Cablewave 738350 3-1/8" EIA Flange (pressurization)
Replies: 2
Views: 350

Re: Cablewave 738350 3-1/8" EIA Flange (pressurization)

The transmitter end is good. It had occurred to me that I could replace them with connectors that will pass the pressurization. I could do what you suggest also. I was hoping to do something that did not mean a significant break in transmission though and was easy!
by DaveSt
Tue Feb 12, 2019 6:43 am
Forum: Ask the Engineers
Topic: Cablewave 738350 3-1/8" EIA Flange (pressurization)
Replies: 2
Views: 350

Cablewave 738350 3-1/8" EIA Flange (pressurization)

Hello all. In a month or so I have to return to a site to do some repairs on the pressurization system. I was there last month and the dehydrator had failed from old age and because the feeder would not pressurize, so it had run until it died. The dehydrator will be replaced as it is too far gone. T...
by DaveSt
Mon Feb 04, 2019 1:44 am
Forum: FM Radio
Topic: High Reflected Power Puzzle
Replies: 33
Views: 1956

Re: High Reflected Power Puzzle

To properly shut down the amplifier with the bias, it is not sufficient to remove the bias voltage. It needs to be driven to a negative voltage of several volts. For the harmonics, usually the output filter after the pallet will have elliptical sections to knock out the second and 3rd harmonics and ...
by DaveSt
Fri Jan 25, 2019 11:21 am
Forum: Digital Television
Topic: Troubles in SFN network
Replies: 1
Views: 236

Re: Troubles in SFN network

DVB-T is a lot less robust than DVB-T2 in this situation. Getting the modulation to be identical with different modulators will be a challenge. I would say you have two priorities. 1. You need to be able to remote control/monitor the transmitters so that you can see any alarms such as loss of synchr...