Question 1

I’m looking at the Optical mini-node -CATV RF Receiver /transmitter and was wanting to know if I can directly connect it to the coax coming from my cable provider instead of using a splitter to run it thru your optical reader then splitter as depicted in the drawing.

Accepted Answer

the mini-node is an optical receiver with Return Path I have a coax demarc from the cable company that carries both internet and TV that I want to convert to fiber optics to enable me to transmit the signal less than a mile to a fiber/RF coax converter to enable me to use the cable companies box to watch TV and have high speed internet. So in this case you need an RF Optical transmitter; then you need an Optical RF receiver with Return Path, and finally you need a Return Path Receiver; so 3 products total and at least 2 strands of singlemode fiber. Would this device “L-BAND over Fiber Tx+Rx Basic 1 Ch Kit” be more practical for what I am trying to accomplish? No this is the wrong equipment for your application Lband is satellite, which is in a different frequency range then CATV So because I’m transmitting data it would require me to utilize these three devices, correct? Data and CATV in the RF band; yes correct. I would also need to install and use single mode duplex fiber optic cable is that correct? Yes, minimum 2 strands. One to send and one to receive. So for each location I wanted to have cable and high speed internet I would need to run two strands of fiber for each location? not necessarily, it depends what your fiber layout looks like or the general design itself https://thorbroadcast.com/ is sharing a file with you. 1_image.png - (Size:530.37 KB) in this kind of design you can use an optical splitter to minimize some of the products needed. Are you able to provide me with a price for these four pieces of equipment, optical transmitter, splitter, optical receiver and the little gray box that goes into the house? Sure what size optical splitter do you need? You mention a mile of fiber but do you have an optical budget reading on those strands? Transmitter 4mW starts at $1995.00 but if you need a larger splitter, then you 'll need a stronger transmitter. 1 to 4 and I saw you had both a rack mounted model and mini version so is there a price difference with these? 4 channel return path receiver MiniNode with Return Path how about the optical transmitter? 1x4 rackmount splitter is 400, the compact model is 350 do you offer the fiber optic cable I need in custom cut lengths with connectors? yes we can do that,

Question 2

Here’s a snippet of what I need   This project is for the addition of one three-story building on an existing school campus. Floors 2 & 3 include a total of 17 classrooms and 21 TV outlets. The drawings do not provide a clear explanation of the distribution, but my thinking (please correct me if I’m wrong) would be to include 21) receivers (one per TV outlet) and 2) 1x16 splitters. Does that make sense?

Accepted Answer

I think the part that maybe throwing you off is that the way we calculate optical power needed is in reverse. The splitter is the largest optical loss device in the drawing, so we count backwards on how many receivers you need, then splitter, then in turn we tell you how much power the transmitter needs to have.    You can not put two 1x16 splitters in line with that transmitter, the signal won't even make it past the splitter. It's too much loss.    That's why I'm asking you not to look at the picture, but to tell me exactly what the needs of the project are. So if you have 21 end points then you need a 1x32 splitter https://thorbroadcast.com/product/1-x-2-to-1-x-128-fiber-optic-couplers.html/228 But since you're dealing with one building and different floors, you should be able to get away with one transmitter, 1x32 splitter, and then XXX receivers; I think 21 as you mentioned is probably the correct number.  So long as they have singlemode fiber in place, we can help with everything else.  Just make sure it has SC/APC connectors; otherwise we also sell jumpers if you get any other kind of termination installed.

Question 3

I wanted to ask, the F-MININODE-2RP-HP, is it possible to turn off the RF output via the network?

Accepted Answer

Unfortunately, it is not possible to turn off the RF output of the F-MININODE-2RP-HP via the network. The unit will always output RF. You consul only attenuatore the RF output up to 15db   However, if your application requires the RF to be turned ON/OFF, we do have a 2x1 RF switch that you can possibly use with the connection to the MININODE.  You would connect the MININODE RF out to the RF switch, and then you can control it by switching to Input #2, which has no RF supplied.     Here is a link to the product:     https://thorbroadcast.com/product/1-1000mhz-rf-redundancy-switch.html

Question 4

We have an internal cable TV distribution system that was designed by a consultant. The design uses mostly high-power mini nodes. When I run the calculations for taps and attenuators, most of the cable distances are around 150 feet or less. Because of the high output level, I’m finding that I need to add attenuators on many of the runs. So my question is: If the distances are relatively short, is there any advantage to using lower-power mini nodes instead of high-power ones so that I wouldn’t need so many attenuators throughout the system?

Accepted Answer

dam: Just to clarify — the distances you’re referring to are RF distances on coaxial cable, not the optical fiber portion of the system, correct? Customer: Yes, that’s correct. I’m referring to the RF side on the coax. Adam: Okay. What equipment are you connecting to the output of the mini node? Are you going directly into TVs, or are there splitters or taps in between? Customer: We’re using multitaps. The taps feed the TVs directly. Adam: Understood. And what value taps are you using? Customer: We’re using 26 dB taps. Adam: That explains it. Our mini nodes output around +45 dBmV RF level. If you use a 26 dB tap, the drop port already introduces about 26 dB of loss, which means the signal level going to the TV will be roughly: +45 dBmV − 26 dB = about +19 dBmV That level is actually perfectly acceptable for a TV. Most TVs can reliably receive signals in the range of roughly +5 dBmV to +30 dBmV. Customer: I see. In my calculations I started with the +45 output, then subtracted the 26 dB tap, and depending on the cable distance I thought I needed additional attenuation. I may have been using too strict of a target range. I was trying to keep the signal around 0 to +10 dBmV at the TV. Adam: Yes, that range is a bit too strict. TVs can handle a much wider signal range than that. We test these systems regularly, and even signals up to +30 dBmV typically work without issues. Since the 26 dB tap already provides the necessary attenuation, you usually won’t need additional attenuators unless you are feeding the TV directly without a tap. Customer: That makes sense. So I was just being too conservative with my target signal level at the TV. Adam: Exactly. Because the tap already introduces sufficient loss, you can typically use the system exactly as designed without adding extra attenuators. Customer: Great. That answers my question. Thank you.

Question 5

Why QAM Channels Are Not Locking on Fiber Nodes (Mini Node / R-PHY) – Troubleshooting Guide When installing a fiber optic mini node (such as R-PHY / RHPH nodes), a common issue encountered in the field is QAM channels failing to lock, even when the system appears operational. This article explains: The most common cause Step-by-step troubleshooting procedures Best practices for RF level balancing When installing a fiber optic mini node (such as R-PHY / RHPH nodes), a common issue encountered in the field is QAM channels failing to lock, even when the system appears operational. This article explains: The most common cause Step-by-step troubleshooting procedures Best practices for RF level balancing Root Cause (Most Common)  RF output level is too high (overdriving the tuner) Typical fiber nodes output: +42 to +45 dBmV RF Most QAM tuners expect: ~0 to +15 dBmV optimal range If the signal is too strong: Tuners will not lock Signal becomes distorted More power ≠ better signal

Accepted Answer

Step-by-Step Troubleshooting Procedure 1. Check Optical Input Power Access the node display Look for optical input (example: 0.8 dBm) ? Acceptable range: Typically -8 dBm to +2 dBm ???? If within range → proceed ???? If too high → consider optical attenuation 2. Verify RF Output Level Fiber nodes typically output very high RF levels Measure using: RF meter Spectrum analyzer ???? Expect: ~+42 to +45 dBmV 3. Add External Attenuation Use RF pads (attenuators) Example: 30–40 dB attenuation may be required ???? Goal: Bring signal down to ~0–15 dBmV at the tuner 4. Enable Internal Attenuation (Critical Step) Most nodes include built-in RF attenuation: Navigate to: A1 (Forward Path Attenuator) Set value: Up to 15 dB ?? Important: You may need to press and hold buttons to activate adjustment mode 5. Combine Internal + External Attenuation Best practice: Use internal attenuation first Fine-tune with external pads Example: 15 dB internal 20–30 dB external 6. Re-Test QAM Lock After adjustment: Check if channels lock properly Verify with: RF analyzer (MER / BER) TV or STB ? If locking → issue resolved ? If not → continue balancing Key Insight ???? Too much RF power causes failure — not too little QAM signals are digital: They either lock cleanly or fail completely Overdriving causes: Distortion Poor MER No lock Forward Equalization (E1 Setting Explained) You may see a setting like: E1 – Forward Path Equalizer What it does: Balances signal levels across frequencies Compensates for cable losses (higher freq loss) When to use: Long coax runs Uneven channel levels ???? Think of it as: “Leveling” all channels evenly Return Path / Laser Behavior If only using forward path: Return laser is: Inactive by default Activates only when RF input is present (burst mode) Best Practice: Keep unused optical ports covered Prevent dust contamination Recommended RF Level Targets Location Recommended Level Node Output +42 to +45 dBmV After Attenuation +0 to +15 dBmV Ideal Target ~+5 to +10 dBmV Quick Troubleshooting Checklist ? Check optical input power ? Measure RF output ? Add attenuation (external) ? Enable internal attenuation (A1) ? Re-test QAM lock ? Fine-tune levels Real-World Case Insight In a recent installation: Node output was too hot Even with 35 dB external attenuation, QAM failed Adding 15 dB internal attenuation: ???? Immediately restored channel lock Conclusion The most common cause of QAM lock failure in fiber node installations is excessive RF signal level. ???? Proper attenuation and balancing are critical. If your system shows: No lock Intermittent lock Unstable channels ?? Always check RF levels first. Need Help? Thor Broadcast engineers can assist with: System design RF balancing Remote configuration ???? Call us anytime ???? www.thorbroadcast.com

Question 6

Fiber RF Over Single Mode – System Design Q&A (Customer Consultation )  I’m working on a project where we need to deploy RF over single-mode fiber, and I’d like help selecting the correct transmitter, nodes, and receiver.

Accepted Answer

System Requirements Q: How many splits will the system have? Mark: We’ll have a 4-way split, with: 3 active fiber runs 1 spare for future use Distances: Longest run: ~2,250 ft (with 2 splices) Other runs: ~750 ft Q: Will there be a return path? Mark: Yes, there will be a return path. Return frequency: ~21 MHz Forward starts around 50 MHz Adam: Perfect—that’s a standard forward + return CATV system. Transmitter Selection Q: What transmitter should be used? Adam: You have two options depending on future expansion: Option 1 – Current Need (4-Way Split) Use a 4 mW transmitter: ???? https://thorbroadcast.com/product/4-mw-catv-rf-over-fiber-tx-45-870-mhz.html Ideal for: 1×4 splitter Short to medium fiber runs Most cost-effective solution Option 2 – Future-Proof Design (Recommended) Use an 8 mW transmitter: ???? https://thorbroadcast.com/product/8-mw-catv-rf-over-fiber-tx-45-870-mhz.html Supports: 1×8 splitter expansion Longer distances / higher losses Provides additional optical power margin Adam’s Recommendation: ???? If future expansion is possible, go with the 8 mW transmitter Receiver (Node) Selection Q: What node should be used on the receiving side? Adam: Use the Mini Node with Return Path: ???? https://thorbroadcast.com/product/optical-mini-node-catv-rf-receiver-with-return-path-8230.html (Model: F-MININODE-2RP-HP) Supports forward + return RF High RF output level Designed for CATV distribution ???? You will need: 1 node per fiber leg (4 total) Fiber Splitter Selection Q: What splitter should be used? Use PLC Optical Splitters: 1×4 Splitter (Current System) ???? https://thorbroadcast.com/product/1-x-2-to-1-x-128-fiber-optic-couplers.html/225 Designed for 4 outputs Lower insertion loss 1×8 Splitter (Future Expansion) ???? https://thorbroadcast.com/product/1-x-2-to-1-x-128-fiber-optic-couplers.html/226 Allows system expansion Slightly higher insertion loss Ideal for long-term scalability Q: Should unused ports be terminated? Adam: Yes: Splitters include protective caps Always keep unused ports covered to: Prevent dust contamination Maintain optical performance Connector Type Q: What fiber connectors are required? Adam: Use: SC/APC connectors (green) If different connectors exist: Use conversion jumpers (LC, ST → SC/APC) System Design Recommendation Adam: For your project, I recommend: 8 mW transmitter (future-proof) 1×8 PLC splitter 4 × Mini Nodes (F-MININODE-2RP-HP) Return path receiver (if required at headend) ???? This provides: Reliable performance Expansion capability Proper optical power margin   Summary   This system design includes: ? RF over single-mode fiber ? Forward + return path operation ? 4–8 way optical distribution ? High-performance CATV mini nodes ? Scalable architecture for future expansion Need Help? Thor Broadcast can assist with: System design Product selection RF level balancing   ???? Contact our engineering team anytime

Question 7

We’re working on a project with a fiber backbone. We’re trying to deliver internet service to cable modems via a CMTS, and I’m looking to speak with someone familiar with your broadcast equipment, specifically the F-RF-1310-TX equipment. Let me explain the application. We have a headend with a CMTS, which communicates with cable modems out in the field. It handles the RF frequencies for both upstream and downstream communication. From the headend, the signal goes out to a fiber node, which may be around 2,000 feet away, over single-mode fiber. At the node, the fiber input is converted back to coax/RF, which then distributes the signal further. Because of the size of the property, we may eventually need 6 to 8 fiber nodes, each fed by its own single-mode fiber in a star topology back to the headend. My first question is: if each fiber node is sending a signal back to the headend, would I need a separate F-RF-1310 receiver for each node? Or can I combine them through a fiber splitter and bring them back into one receiver?

Accepted Answer

Adam: What you are describing is a typical forward RF path, generally in the 45 to 1000 MHz range, along with a return path in the 5 to 45 MHz range. Is that correct? John: Exactly. Adam: Okay. The design depends on how many nodes you plan to use. We offer transmitters from 4 mW up to 32 mW. If you choose a stronger unit, such as 16 mW or 32 mW, you’ll have enough optical power to split the signal more easily — potentially to 16 or even 32 outputs, depending on the loss budget. For example, if you only need 8 nodes, an 8 mW transmitter may be enough. If you want a more universal solution for multiple sites, a 32 mW transmitter would likely cover all cases. John: Wouldn’t a 32 mW transmitter overdrive the fiber node in the field? Adam: No. The reason for using a stronger transmitter is to overcome the insertion loss of optical splitters. The receiver sensitivity at the node is typically around +3 dBm to -9 dBm, but the closer you are to 0 dBm, the more optimal the performance. It’s always easier to attenuate optical power than to amplify it later. John: Do you also carry fiber optic splitters? Adam: Yes, absolutely. We have rack-mount splitters and LGX modules. John: So just to confirm: CMTS → transmitter → fiber splitter → multiple nodes? Adam: Correct. The unit at the headend is the transmitter. John: And at the node, it converts back to RF? Adam: Exactly. The recommended node provides about +45 dBmV RF output. John: Is it outdoor-rated? Adam: We have outdoor options, but typically it’s installed in a NEMA 4 enclosure. No ventilation is required. John: Now about the return path — how do modems communicate back? Adam: The node is bidirectional. The return path (5–45 MHz) is sent back over a second fiber. So each node uses: 1 fiber forward 1 fiber return At the headend, you use return path receivers (e.g., 4-channel units), then combine them and feed into the CMTS. John: And no throughput bottlenecks? Adam: No — the node acts like a media converter (RF ↔ fiber). It does not limit throughput. The CMTS manages all bandwidth and scheduling. John: Good — because we may have 500+ modems, maybe ~100 per node. Adam: That’s fine — same as coax architecture. Just confirm your return band is truly 5–45 MHz. John: I believe so — about 8 upstream / 8 downstream channels. Adam: That will work. John: Can you send me links and a quote? This is for boat harbors — about 1,000 boats, each dock serving 40–50 users. I need to calculate: RF levels Split losses Whether I can avoid line extenders Adam: Understood. Typical losses: 1×4 splitter → ~7.5 dB 1×8 splitter → ~11 dB Coax loss ~2.5–5 dB per 100 ft (depending on cable) You may place nodes per dock or per group of docks depending on layout. John: Exactly — depends where fiber is available. Adam: I recommend building a test section first. We also have an RF-over-fiber specialist we can involve if needed. John: Good idea. This could scale to 8–9 harbors, so it needs to be solid. Are these used by cable operators? Adam: Yes — these are carrier-grade solutions used by commercial operators. John: And you’re the manufacturer? Adam: Yes — fully controlled design and production. Also NDAA compliant. Adam: Where is your RF coming from? John: Currently mostly empty spectrum — just CMTS channels. We may add off-air channels later. Adam: We also offer QAM / ATSC modulators if you decide to inject channels. John: We’ll evaluate that later. Right now, priority is avoiding line extenders. Adam: Makes sense — return path gets complicated with amplifiers. Fiber simplifies that significantly. John: Exactly. That’s why we’re moving to fiber. Adam: Right — fewer amplifiers, longer distances, easier balancing. John: Perfect. Please send: Product links Contact info Initial pricing I’ll review and get back to you this week. Adam: Will do. I have your email — I’ll send everything shortly. John: If this checks out, we’ll be ordering within a few weeks. Adam: Great — once you finalize node count and layout, we’ll size: Transmitters Splitters Return receivers Rack space (~8U estimated)   8 mW TX: - https://thorbroadcast.com/product/4-mw-catv-rf-over-fiber-tx-45-870-mhz.html Fiber Node: https://thorbroadcast.com/product/optical-mini-node-catv-rf-receiver-with-return-path-8230.html Return Path Receiver: https://thorbroadcast.com/product/4-ch-cable-tv-return-path-receiver.html

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Item	Unit	Technical Parameters
Optical Parameters
Receiving Optical Power	dBm	-9 ~ +2
Optical Return Loss	dB	>45
Optical Receiving Wavelength	nm	1100 ~ 1600
Optical Connector Type		SC/APC IMPORTANT NOTE* (it is very important to interface our unit with SC/APC - Angle Polished Connector to avoid any light reflections. If your fiber is terminated with the SC, ST, FC /PC flat connector, you need to use an optical jumper from PC type to SC/APC for proper conversion.**
Fiber Type		Single mode
Link Parameters
C/N	dB	≥51		Note 1
C/CTB	dB	≥60
C/CSO	dB	≥60
RF Parameters
Frequency Range	MHz	45 ~860/1003
Flatness in Band	dB	±0.75
		( F-MININODE-2RP-HP-B one output)	( F-MININODE-2RP-HP two output)
Rated Output Level	dBµV	≥ 108	≥ 104
Max Output Level	dBpV	≥ 108 (-9 ~ +2dBm Optical power receiving)	≥ 104 (-9 ~ +2dBm Optical power receiving)
		≥ 112(-7~+2dBm Optical power receiving)	≥ 108 (-7 ~ +2dBm Optical power receiving)
Output Return Loss	dB	≥16
Output Impedance	Ω	75
Optical AGC Range	dBm	(-9dBm / -8dBm / -7dBm / -6dBm / -5dBm / -4dBm) - (+2dBm) adjustable
Electrical control EQ range	dB	0~15
Electrical control ATT range	dB	0~15
General Characteristics
Power Voltage	V	A: AC (150~265)V	D: DC 12V/1A External power supply
Operating Temperature	°C	-40~60
Consumption	VA	≤ 8
Dimension	mm	190 (L)* 110 (W)* 52(H)

Optical Mini-node - CATV RF Receiver with Return Path - High RF Output Power 48dBmV

Description

RF over Fiber CATV TF Mini-node - dual band transceiver. Thor F-MININODE-2RP-HP series transceivers are wideband radio frequency optical modems for bi-directional broadband communications. This platform can have a custom configuration.

Features

Drawings

Application Examples

Model Selection

F-MININODE-2RP-HP 2 Fiber High RF output Power Mininode, 2 RF outputs - 45dbmV each

F-MININODE-2RP-B Customized 2 Fiber High & LOW RF output Power Mininode, 2 RF outputs - One output +48dbmV, The second output +38dbmV

F-MININODE-2RP 2 Fiber low Power Mininode, 2 RF outputs +35dbmV each

Specification

Question and Answers

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