Revisions:
- 20230618: written on the last day of broadcast at Terschelling
- 20230622: new information on FM antenna ground issues
Equipment Needs
Major Components:
- FM: Antenna
- FM: Transmitter
- Wireless Audio: Receiver
- Wireless Audio: Transmitter
- Mixer: Zoom H6 with SD card
- Mics: 3 Rhode lavalier, 1 ambient
- Macbook
- Ipad
Topology
((x))
|
|
| ANTENNA | | TRANSMITTER |
|+++++++++++++++++| |+++++++++++++++|
| Sirio 88-108Mhz | | PocketFM |
| | | |
| N-connector|——–|BNC-connector |
^ | DC-Power|—-100Watt_Cable—-[AC]
| | Audio out RCA |
L400-coaxcable—-‘ L\ /R
|
| <–rca to stereo cable
|
L/ \R
| WIRELESS_AUDIO |
|++++++++++++++++++++++++++|
| Denon DN202WR |
| |
| internal limiter control |
| DC-Power|–[AC]
| 2.4Ghz receiver |
|
((wireless))
|
| WIRELESS_AUDIO |
|++++++++++++++++++++|
| Denon DN202WT |
| |
| 2.4Ghz transmitter |
| DC-Power|–[AC]
| Audio in Stereo |
L\ /R
|
| <–rca to stereo to
| mini-jack cable
| AUDIO_MIXER | |
|++++++++++++++++++++++++++++++++++| |
| Zoom H6 | |
| Line OUT mini-jack|–‘
.———|Mic 1 XLR (red) |
| .——-|Mic 2 XLR (ambient) |
| | .—–|Mic 3 XLR (yellow) | | MACBOOK |
| | | .—|Mic 4 XLR (blue) | |+++++++++++|
| | | | | LR Attachment mini-jack (macbook)|———– |Stereo-out |
| | | | | Isodora |
| | | | <— xlr cables | wifi |
| | | | |
| | | `—[Rhode-XLR-to-Micro-jack]—[Rhode-Mic] ((wireless))
| | | |
| | `—–[Rhode-XLR-to-Micro-jack]—[Rhode-Mic] | IPAD |
| | |+++++++++++++++|
| `——-[Senheiser-Mic] | Touchosc app |
| | Simple layout |
`———[Rhode-XLR-to-Micro-jack]—[Rhode-Mic]
Setup
These steps build up in a specific order, where after each step we test the setup before moving to the next step
- Setup FM transmission
- Setup Isodora controller
- Setup H6 mixer
FM
Check you have:
- PocketFM
alternative: FM 15-25watt transmitter such as those by pcs-electronics.com - PocketFM 100watt power cord
- Sirio GP 87-108Mhz LB N-Connector Antenna
alternative: tunable Sirio GP FM antenne FM GPA 66-108 - L400 cable with N-connector’s
alternative: generic RG-58 50-ohm cable - N-to-BNC converter (antenna is N, PocketFM is BNC)
- A simple FM Radio to test with
- (optional) Denon 2.4Ghz audio transmitter and receiver
DO:
- Never turn on PocketFM without antenna connected.
- Turn transmit power to 0 when storing, as caution
- Setup Antenna
- Insulate antenna brackets from the pole/mast to avoid a situation where pole is already grounded and causes a problematic electrical loop. (see issues section). Or try to avoid putting on poles with other antenna types that require pole grounding.
- Make sure to put on pole that does not have other antennas.
- connect to Pocket FM
- Connect your audio player or source audio to the RCA input of PocketFM
- On PocketFM
- enter User Interface. Password: 000000
- Change input to Analog
- Change FM Frequency to desired frequency
- Change Power to 12% which is around 2-3 watt
- Change Station Name (difficult to do, leave it to end)
- Check with your test FM radio receiver
- If you want to connect Analog audio remotely then setup the Denon transmitter and receiver
ISSUES:
- In Terschelling PocketFM had power reflection issues. Powering transmitter more than 3watt would caust analog audio to cut out. Internal or stream/digital audio would still work. Powering transmitter more then 10watt would create up to 10% reflection. Thus 10watt power would show a reflection of 1watt (or 10% of total power). Normally reflection should never be more then 4% of total power. Above 10watt even internal/digital audio would cut out. This issue did not appear when testing in amsterdam. In amsterdam: observed that analog would stay on but get very noisy above 2.5watt. Internal would stay clean up until and passed 10watt (50% total power). With 10watts internal audio there was only 0.3watt reflection, well within limits. Even at 15watt 100% internal audio was clean with only 0.3w reflection. We do notice though that 100% power only gives 13watt and 80% 12watt and 60% 12watt. So above 60 it seems there is little change.
Solutions:- (20230622) Likely put antenna on pole that was grounded. This suspected because pole had another antenna that may have required grounding. This ground loop back could damage transmitter.
Isodora
Check you have:
- Macbook with Isodora
- Isodora sketch and files
- iPad
Do:
- Ipad
- Connect Ipad to wifi
- make note of Ipad IP address, we need it on macbook isodora sketch
- Start TouchOSC app
- Select Simple layout
- Set the IP address of the server in touchossc to the IP address of the macbook
- Macbook:
- Run isodora sketch and start some interview or sample audio
- The sketch has a controller window with buttons. Click Start
- Check you have audio coming out
- Set TouchOscIp in the sketch found in top left, to the IP address of the Ipad
- Check that the ipad can start and stop the audio
Zoom H6 Mixer
Check you have:
- Zoom H6 with attachment
- USB micro-usb power
- SD Card
- 3 to 4 XLR cables for mics
- 3 Rhodes lavlier mics
- 3 to 4 Rhode XLR to Stereo converters
- 1 ambient mic
Do:
- Connect Zoom H6 attachment
- Connect Stereo cable between H6 attachment and Macbook headphone jac
- Connect mics
- [red] co-host
- Rhode lavalier mic with [red] tape goes into stereo extension cable
- extension goes into rhode xlr to stereo connector
- xlr connects between rhode converter and H6
- [yellow] host
- Rhode lavalier mic with [yellow] tape goes into into rhode xlr to stereo connector
- xlr connects between rhode converter and H6
- [blue] guest
- Rhode lavalier mic with [yellow] tape goes into into rhode xlr to stereo connector
- xlr connects between rhode converter and H6
- Turn on Zoom H6
- Check levels of Macbook input and mics
- Check that the SD card is inside and Zoom shows a folder name on user interface