Doug (WA5ETS) provided net control training during the Saturday, February 26, 2022 OCRA net. The training has been posted to YouTube and is available by clicking the link below.
Laurie Meier, N1YXU
Doug (WA5ETS) provided net control training during the Saturday, February 26, 2022 OCRA net. The training has been posted to YouTube and is available by clicking the link below.
Laurie Meier, N1YXU
Remember the HF phone patch that used to be commonplace in the ham shack years ago? How about a video conference HF patch? Or for that matter, flip a switch and it’s a video conference to VHF/UHF patch?
Bill, N8BR does not have an HF station at his QTH, but that did not stop him from listening to the net and Dan, KR4UB passing on his comments to the net.
Dan hosted a video conference and invited Bill to join the OCRA Monday Night 10M Net on 28.450 via video conference. Ham station audio is fed into the computer running the video conference application. A simple switch of the video conference microphone device driver setting from the normally used Logitech HD camera microphone to the computer line-input brings the ham radio receiver audio and Dan’s Heil headset microphone audio into the video conference.
Much of the equipment used and shown below has origin in other usage and has morphed into a small home audio studio serving multiple purposes. This application is a good example of the versatility it can provide.
The video conference “audio patch” application demonstrated here might could be built using some of the audio interfacing devices found in today’s ham shack for computer sound card driven amateur radio communication modes. However, if undertaken getting the audio chain correct might still require use of external audio mixers, attenuators, and additional isolation and perhaps impedance matching transformers, and instrumentation to get the sound right.
The ham radio connections in this setup uses a W2IHY Technologies Equalizer that has multiple microphone inputs, one used for the Heil Headset microphone and a second input is used for the video conference inbound audio feed. The internal microphone amplifier gain is adjustable to ensure appropriate drive level to the selected ham transmitter with the output fed via an internal isolation transformer for RFI protection. The output is switch selectable to one of two ham station transmitters, in this case a Yaesu 8900 VHF/UHF and the Elecraft K3s transceiver. The phone jack output is an outbound (ham transmitter mic input) audio monitor output that is also connected to one of the Roland Monitors as described below. The equalizer interconnection ports available for all audio outbound to the ham radios are shown below.
Two Roland CM-30 Mini-Cube Studio Monitors in an interconnected stereo link configuration provides multiple audio channel mixer inputs as shown below on the one of the two units. One of the CM-30 units is used for all inbound (video conference incoming audio & ham radio receiver audio) feed mixing. Outbound (ham transmitter microphone inputs & video conference outbound) audio is separately mixed in, permitting audio from all sources to be monitored on the Heil headset as a final control operator quality check. Roland, a major manufacturer of musical instruments and sound stage equipment describes the CM-30 as a multi-purpose portable mixing monitor for the home-studio and portable live monitoring onstage applications.
A Jensen two channel isolation transformer previously used in a home theatre application is used to provide RF & ground loop isolation between the ham station and computer audio connections. Braid ground strapping bonds all equipment to the common station ground.
A recently added connection for the video conference audio output will permit that feed to be mixed into the Elecraft HF or the Yaesu VHF/UHF mic input so video conference folks have half-duplex two way audio communications and can join the rag chew. None of this will be automatic and will require the control operator to set up the “audio patch” and operate the PTT control, the same as was required by the FCC back in the days of “phone patch” operations.
Does the above discussion of all the inbound, outbound, audio mixing sound like one giant circular loop? Not surprising… Ever wonder why speakerphones, telephone handsets, cellphones, bluetooth headsets, hearing aids and now video/audio conferencing…. any accoustic environment where speakers and microphones are in close audio proximity doesn’t turn into an enormous squealing audio feed back loop? You’ve probably heard that many times with public address systems. What’s the magic? What invention took place and has been deployed in telephone systems from the beginning? The telephone hybrid transformer, used in bidirectional audio paths where two audio directions are combined in to a single audio channel. This function is essential in today’s world of communication devices and typically done with digitial signal audio processing. The mixing and combining of audio paths described in the above setup had to be done in a way to avoid generating an audio feedback loop at several possible points in the circuit. The bidirectional processing or half-duplexing of conference audio by a video conference service is also a necessary ingredient.
You’ve probably have experienced this effect in ham gatherings when you transmit on with your HT into a repeater and someone close to you has their HT volume turned up on the same repeater you are using. You’ll hear your own voice coming through being delayed in time or an outright audio feed back squeal occurring. The delayed audio echo effect is caused by an audio delay line in the repeater controller for the purpose of removing squelch noise bursts at the beginning and end of every transmission into the repeater and also for masking DTMF repeater control tones sent to the repeater. The OCRA 442.150mHz repeater is programmed to use a 70 msec audio delay to accomplish the above purposes. Sounds short, but very disorienting to hear your own voice delayed in time as you try to speak!
The conference to repeater audio bridge described in this article can have similar echos in the video conference side when repeater radio transmissions are recirculated from radios in the video conference. Video conferences can be more vulnerable as downloaded video conference applications typically provide a microphone audio AGC (automatic gain control) that if checked will adjust your computer/conference device microphone gain on the fly to make all voices at the same level in the conference. This is a good thing for the conference, but stray radio audio can be problematic.
However, the effect can be totally eliminated by proper audio protocols being practiced by those in the video conference. Those procedures will be described in a separate article.
While the equipment used here may border on overkill, hopefully the above audio discussion explains the necessity and there are advantages especially in the ability to measure, set and monitor audio levels at the key points in the audio chain. Among other uses, this setup has been used for some years as the final over the air audio level checks before a newly built repeater is deployed to a difficult to reach site such as the OCRA 442.150 mHz repeater located high up on the TV tower.
The setup is also used for periodic repeater checks and troubleshooting when repeater problems have arisen. The computer can do extended VOX triggered recording of the repeater to catch intermittent problems and spectrographic analysis software can be helpful on certain types of repeater issues.
Two computer applications were used to adjust the audio levels for optimum quality. The first program called Spectrogram, used in a vast range of fields, was written many years ago by Richard Horne, an Electrical Engineer working for the U.S. Navy. The second program Goldwave, a professional digital audio application was used to analyze historic recordings of the Moon landing, including establishing the “missing word” from astronaut Neil Armstrong’s famous line.
In summary, the building of this setup has been heavily influenced by other audio interests & needs, but also by experience in building the OCRA repeaters for the last 20 years. Mentoring by Danny, K4ITL in the early days of repeater building taught what it takes to set up repeaters to have excellent audio quality.
from Jack, KM4MBG & Chris, KK4VBE
There will be a Saturday morning video conference to help fill the void left by the cancelation of our celebrated ham breakfasts due to the Covid-19 pandemic. That net usually doesn’t last long, so we’ll try to start at 9:45am local time.
Directions for Joining:
Make sure you have a computer with good microphone and speakers (a headset often works well). There is no software to install. Use your web browser to go to URL address posted in the video conference announcement note on the OCRA-DFMA Joint Email list at the appointed time.
Thanks to Chris, KK4VBE, for hosting the server. Hope to see y’all online.
If you do not have a computer with a camera and or mic but have a smartphone you can still join in on the video call. You will need to install the Jitsi app form the app/play store.
Then at the appointed time click the link in the recently posted note on the OCRA-DFMA Joint Email list and your web browser will open and give you the option to launch the app.
73, Chris KK4VBE
Many thanks Jack & Chris!
Tonight we had 14 check-ins.
1. KZ1X – Steve: Very interesting RARS with fewer dealers this year. Some not there due to illness.
2. NC4CX – Butch: Really enjoyed the RARS fest and seeing folks that he has not seen in quite some time. Good to finally meet Bruce and Laurie. Also saw many of the regulars on the Monday night net. Very little radio activity but did get his 6 meter beam up with some good preliminary reports. Now he can switch from his 40 meter I-V to the new antenna.
3. KX4P – John: Able to copy everyone so far. Really enjoyed going to the RARS fest with a friend that drove in for the weekend. Brought lots to sell but ended up bringing everything home again. Did end up purchasing a few things. Using a Collins S-line tonight.
4. KR4UB – Dan: Also enjoyed RARS fest – the most enjoyable part were the eye-ball QSOs. Enjoyed the after RARS trip for super hamburger lunch. Looking forward to the Tar Heel 10 mile run.
5. KJ4UZU – Clint: Real good to see so many familiar faces at RARS. Did not bring a new HF radio home from RARS. Did purchase a couple 6 meter FM HTs and they both work! Great to see Wayne after such a long time. Now up to 93 on 80 meters – getting closer. Got South Shetland for a new country and it was on 80! Now at 280 total confirmed. Now looking forward to Durham Fest.
6. K4FD – Dan: Good evening to everyone – been off the air for a couple years and got back on a couple weeks ago. Heard about the 10 meter net and wanted to check in. This is the first time he checked in. Been spending some time working on antennas. Also really enjoying 17 meters. The band noise has been very low allowing Q5 contacts without huge signals. Also enjoyed RARS and purchased a few things including some small tools. Able to copy everyone on the net!
7. KU4GC – Dee: RARS was fun and the club tables did fairly well. DFMA made about $300.00 net after paying for the tables. Don’t yet have the OCRA final $$ but in the last minute one of the ICOM rigs went for $400.00 that will certainly help the final results. Have a DFMA Board meeting tomorrow night. Also looking forward to the Tar Heel 10 mile race. Not much HF work – Clint is 1 ahead on 80 with Dee’s total being 92. At 236 on all band DXCC. Still have an ICOM 706 for sale – had 2 one left so Dave (NA4VY) still has an opportunity.
8. W4BOH – Wilson: Also enjoyed RARS and controlled his purchases. First time ever he did not purchase anything from the club table. Enjoyed seeing Laurie – hope she did well. Saw a couple Hammarlund receivers. Bought JR’s amp – it is a big Heath Kit with (2) 3-500s. This will be one of the next Land of Magic amps. (Perhaps a SB-220 or SB-221 depending on age.) Good to see some regulars but some of the regulars were missed. Been working on taxes almost all day. Greta was visiting for a few days and just went back home. Still in need for a food committee for Field Day – really needed to keep the food moving on Saturday night / Sunday morning.
9. NA4VY – Dave: Running the Yaesu FT1200 today. Hope it sounds good as he is using he mic that was purchased from Bruce. Made it to RARS and enjoyed walking around seeing people and checking out the boat anchors. Want to get rid of some stuff, so nothing was purchased. Was tempted to purchase the ICOM 706 that was on the OCRA table. Also busy with taxes.
10. KG4NNT – JR: Good to see everyone at RARS last Saturday. Looking forward to the Durham Fest in a few weeks.
11. KK4PH – Lowell: Had company so got to the net late but made it!
12. WQ8U –Mac: Using his only modern radio, the Ten Tec Jupiter. Wilson showed up in Mac’s driveway to help solve a noise problem and pointed out a few antenna related issues. One issue was lack of use – this helps by checking in on the net!
13. KE4VNC/M – Joe in Knightdale – very light copy.
14. N1LN – Bruce: Net Control
Tonight we had 9 check-ins.
1. DFMA membership meeting: April 2 at Bullock’s Restaurant
1. NC4CX – Butch: Unable to check-in last week as he could not hear net control. Did listen to those that he could copy. Did not get on WPX at all this weekend. Listened but nothing new heard. Did work Ivory Coast before they left. Hope they confirm as it is needed. Did get Niger for an all time new one.
2. KZ1X – Steve: Using a different antenna tonight – a 10 meter squalo about 10’ off the ground. His usual antenna is under construction. Worked 12 contacts on WPX and now only 1 short for a SA prefix for Excellence Award.
3. KJ4UZU – Clint: Has rf audio issues with his FT897. Now using the Kenwood and all is fine. Did work a few countries in the WPX contest – about 11 contacts. One new one on 80 – Iceland and now looking for a confirmation. Also worked Western Sahara on 80 and looking for a confirmation. Still stuck at 90 confirmed. Worked Papua New Guinea on 40 from the mobile.
4. W4BOH – Wilson: Nothing new at the Wilson residence. Went to Peter’s over the weekend. Did some metal detecting today with his grandson. Got the Loudenboomer going. Found a power supply issue and also a filter choke issue. Replaced it with a choke from the Land of Magic inventory and now the high voltage is MUCH better. Going to write it up for the link. No new DX – Niger pileups were horrible. Listened Bangladesh – wonder if anyone worked them. Had a very enjoyable trip to the mountains but some rain on the way home.
5. KG4NNT – JR: Able to hear Bruce. Glad to be in the net tonight.
6. KA5ETS – Doug: Wilson came up a few S-Units due to turning his beam. Not going to be able to do much with Field Day this year. Got on 60 meters a few months ago and getting used to that. Running some JT65 around 5:00am. FCC may open more of 60 meters up for wider use. Awaiting their decision. Also now have a vertical for 80 meters with 4 radials. Have worked some Europe and Russian stations with JT65.
7. WA4PSC – Howie: Sorry to have missed the OCRA meeting last week. Been involved driving Sarah around but she is on the mend and actually drove her car the other day. Been working on lots of new projects for Dayton. Trying to get parts with long lead times reduced. Just got in from the machine shop – now eating dinner.
8. KU4GC – Dee: Missed most of the net tonight due to an OCRA Board Meeting. Heard Doug and Howie only. Not much to report. Worked Ukraine on 160 JT65. Also putting some time in on the Link proofreading. Enjoy The Egg and I breakfast.
9. N1LN – Bruce: Net Control
Joel KM4NOU, filled in for Bruce N1LN as Net Control.
Joel reported that he’d had a nice weekend visiting his son and family in Centreville, VA. Grandma always likes to visit the granddaughter, Sierra, who is now 10 months old! Joel took his radio and portable antenna with him and was able to participate in the Virginia QSO party as a Virginia station.
KZ1X (Steve) – a little DXing; some antennae problems
KR4UB (Dan) – administrivia, working on taxes, first pass thru; needs to work on DMFA club minutes (this prompted Joel to remember that he needed to work on OCRA meeting minutes!)
KU4GC (Dee) – confirmation on Thailand, new country; DMFA board coming up; visit to the Egg and I; some power supply problems
KJ4UZU (Clint) – new country on 80, French Polynesia on JT65; a couple of new countries on 80M; looking forward to the weekend contests; worked Ivory Coast on 80M;
W3AHL (Steve) – Been a while since he was on the 10M net; some time working on the tower today, cranked it up today; spent several hours working on ICOM HT; shack computer wouldn’t power up so has to work on that;
KA1HPM (Nick) – with contests over the weekend, enjoyed contesting and some DX; working on digital interface for JT65; heading to Nags Head in May, working on the rig for traveling;
KX4P (John) – using old Collins running barefoot, glad to be heard. Still working on 100 countries confirmed digital (stuck at 99);
KG4NNT (James) – in and out on the second list;
W4BOH (Wilson) – Reporting from the Land of Magic; Working on an old amp, fixed power supply; went out to local greasy spoon for dinner; Some DXing, got Ivory Coast, etc.
We had a total of 10 stations, including KM4NOU as Net Control.
Joel KM4NOU, filled in for Bruce N1LN as Net Control. Bruce was went to a Dook basketball game, but this Tarheel still filled in to let him go!
We had a total of 11 stations, including NCS, so not bad for a holiday weekend, with folks just getting back into town.
Joel KM4NOU reported from NCS that he’d had a very nice holiday, visiting his son and family in Centreville, VA. Joel and Jan got to see seven-month old granddaughter Sierra at the beginning and end of the week, since during the middle of the week, the Centreville contingent made a trip to visit other relatives in Kentucky. That left Joel and Jan in charge of his son’s house, their own two Labrador Retrievers, and also the two ten-month old Labrador Retriever puppies that call it home. It was a Labapalooza! Joel had his HT, and the VHF/UHF in the truck, but didn’t find anyone to talk with on the local repeaters. He did make a trip to the HRO store in Woodbridge, VA, and bought himself a Christmas present: a new Heil HM-12 mic, a pedestal, foot switch, and appropriate cables to hook to his FT-450D.
KR4UB – Dan: Not much happening with him, made it to the Egg and I, and had some neighbors over for NYE. Dan said that Joel’s new mic sounded good 🙂
KM4MBG – Jack: Lots of food over the holidays, but mostly relaxing. He’s wanted to get a 6M antenna, but tried tuning his HF antenna and got an SWR of 1.5, so he’s pretty happy and was able to connect to the OCRA 6M Friday Net. Getting ready for “back to work.”
KU4GC – Dee: Being retired means every day is a holiday! He did a little HF, but it was slow; picked up a couple of new band/countries.
KF4PAB – Lenore: Enjoyed holiday parties, food and festivities, but is now getting focused on getting back to work.
KJ4UZU – Clint: Happy New Year! Not much DX (yeah, like we believe that, Clint!) but did work Belarus on 80M last week. Like others, he’s getting focused on back to work.
K0OUX – Vic: Late coming into the Net, had been talking on another frequency, and didn’t shift sideband when he came onto 10M. Still recovering from a double hit of Chickenpox and Shingles that really hit him hard. We were all happy to hear that he was well on the mend after a rough time.
W4BOH – Wilson: It was a fine holiday! Going to carpool to the DFMA meeting on the 3rd, so the Western Orange contingent will be represented. He’s done little DX’ing, but a few cards are dribbling in. Still stuck at 213 countries. One of the kids got a Yaesu 817 for Christmas, but not much other radio stuff.
KK4PH – Lowell: Just rolled back in from a trip to Pennsylvania, Happy New Year, all! Just got the car unpacked, ate dinner, and turned on the radio. It was good to have time off work; worked on a few projects, including installing radios into his truck (that involved welding a bracket to the transmission hump, so serious work there!).
KA5ETS – Doug: Just back from the grocery store, turned on the radio and caught the Net in progress. Enjoyed Christmas with the family in Nashville, and then the beach for New Years. Has been doing a bit of digital mode radio.
WQ8U – Mac: Wilson had been harassing him about joining the Net, he turned on the radio, and there we were! He had a great, if hectic holiday, with 4 of his 6 kids at home at various times.
Respectfully submitted by Backup NCS
Joel, KM4NOU, filled in for Bruce as Net Control. Bruce was stuck at work listening to vendors trying to sell product to make their end of year quota 🙂
It was a busy night (making it challenging for the rookie NCS!), with 15 stations, plus Net Control, for a total of 16!
WA2ROC, Dick – Not much to report, happy to keep the tubes lit and listen in. Dick gets the “gold star” for early checkin at 7:50PM.
KA2DEW, Tadd – Not much to report, just wanted to be in on the conversations. Still working thru antenna repair (actually, not so much antennas as the support systems for antennas) after Hurricane Matthew. It’s a work in progress.
KW4JY, Calvin – It’s been a while since he was on the 10M net, thought he’d swing by and keep us company.
W4BOH, Wilson – Glad to hear everyone, not much news, Christmas prep is overwhelming radio. However, he did have a banner weekend on 160 CW, with for than 50 contacts. More 160 contacts than he’d ever made before, so he was pretty happy with this!
W3AHL, Steve – Long time since he’d been on the ‘net. Working on setting up computers for volunteer tax work. Also helping to install a radio for KI4KKY in a Jeep, and trying to finish other projects.
KU4GC, Dee – Keeping up with a few nets, worked a couple new country/band combos. Replaced a hard disk with an SSD in one of his computers, and is really happy with the results. Much faster!
KZ1X, Steve – Still planning restore of his receive antenna. Also 40M antenna still broken, and one of his three 80M antennas is not working. Lots of projects. Don’t take your antenna to Steve’s QTH unless you want it to stop working 😉
K0OUX, Vic – Coming to us from Chapel Hill, low noise this evening, but 10M seems to be a bit strange as to who he can hear and cannot.
KM4MBG, Ed – Happy to have the time to be on the 10M net tonight, and looks forward to hearing from everyone.
KJ4UZU, Clint – Good to hear all. Picked up Indonesia on 40M SSB Monday afternoon at 5:30PM, was quite surprised and pleased by this. Has had good luck on 40M lately. Picked up a couple new countries on 80M, and picked up Alaska on 80M.
KF4PAB, Lenore – Using new desk mic, hoping folks can hear well. Most reported that she was coming in well; for some reason Net Control was hearing a lot of noise from Lenore, probably due to geography and antenna orientation. She’s looking forward to the DFMA holiday party!
N1LN, Bruce – Glad to have escaped the vendor presentation in time to check in on the net! His voice was a bit horse due to attending a Duke ladies B-Ball game on Sunday. Had a great weekend for the AARL 160 CW contest. He and his team were in 6th place nationally! He has antenna envy of the first place station, which is located at an old AM radio station next to a salt marsh in New Jersey, with two 300 foot towers!
KR4UB, Dan – Almost missed the net, was watching TV! Working on outside projects before the weather gets colder. Repaired his auxiliary antenna, and fixed his headset. Also looking forward to DFMA!
KK4PH, Lowell – Setting up a new radio that will go in his truck, an FT891. Currently in his house on the desk right now, waiting on a fuse for the truck. It sounded good, tho. As to DX, he talked to South Africa on 40M SSB. Worked on a UHF repeater, and continued the never-ending work on fall leaves.
NA4VY, Dave – Only running 100W tonight, rather than 300W, hopes everyone can hear him (was coming in fine to NCS). Had a really bad RF problem, where he found that if he left the stereo, TV, and phone on at the same time, his 300W radio was leaking RF to all these devices, and his voice was coming out of all the other speakers in the house. He’s still working on this, but thinks some ferrite chokes have helped the problem! At least his XYL didn’t come running when he transmitted to the Net 🙂
Respectfully submitted by Backup NCS
Tonight we had 17 check-ins.
> Don’t forget to sign up for the upcoming OCRA Christmas Dinner Party at the Hillsborough Exchange Club. If you have not already signed up send an email ASAP to firstname.lastname@example.org or call or text him at 919-455-3330 or call his home phone number 919-304-0796. Cost will stay at $18.50 and it will be held on December 12, 2016 with doors opening at 6:00pm and dinner served at 7:00pm.
> The DFMA Christmas Dinner will be held on December 6 and for members only as the club picks up the tab for the dinners.
From Bruce, N1LN… Tonight we had 15 check-ins.
Posted by: “Bruce Meier” <email@example.com>