Balun and unun faq

Proof of Performance / Measurement Results

A customer can ask for personalized measurement results (Vector Network Analyser plots) of the products ordered. These are provided for free, when requested at the time of the order.

What can you expect:

• A graph showing the VSWR as a function of frequency. This is a very flat curve, at low VSWR values, over the entire specified frequency range (and beyond).
• A graph showing the magnitude of the Common-Mode impedance. This is a a smooth curve at high impedance values (typically above 3 kiloohm minimum at the edge frequencies) free of sharp constructional resonances that could cause abrupt phase jumps.
• A graph showing the common mode rejection, as measured in a 50 Ohms environment. This curve will show values of – 30 dB or better over the specified frequency range.
• A grah showing the insertion loss as a function of frequency. This curve shows extremely low loss values over the entire specified frequency range (and beyond).

Power Specifications: ICAS versus CCS

ICAS vs. CCS in BALUN or LINE ISOLATOR power specifications

ICAS = Intermittent Commercial and Amateur Service

as compared to

CCS = Continuous Commercial Service

These two service types were first defined in the power-tube industry. The classical definitions are as follows:

Continuous Commercial Service (CCS) is defined as that type of service in which long life and reliability of performance under continuous operating conditions are the prime considerations.

Intermittent Commercial and Amateur Service (ICAS) is defined to include the many applications where the transmitter design factors of minimum size, light weight and considerably increased power output are more important than long tube life. In this service, life expectancy may be one-half that obtained in Continuous Commercial Service.

Under the ICAS classification are such applications as amateur transmitters, and the use of devices in equipment where transmissions are of intermittent nature. Intermittent operation implies that no operating or ‘on’ period exceeds 3 minutes, and every ‘on’ period is followed by an ‘off’ or standby period of at least the same or longer duration.

As applied to passive amateur radio products like BALUNs, LINE ISOLATORS, FILTERS, POWER ATTENUATORS, COAXIAL CABLES and ANTENNAS, ICAS does not imply reduced device life, as these devices are not regarded as consumables. Rather, ICAS in such an environment implies de-rating to keep the product’s temperatures within its maximum ratings. Thus, ICAS suggests a limited operating or ‘on’ period followed by an ‘off’ or standby period of at least the same or longer duration, whilst CCS assumes extended periods of continous operation, at reduced output . As such, appropriate de-rating not only concerns VSWR, but also modulation type, TX/RX duty cycle and environmental conditions.

For amateur radio use, the following recommendations apply:

Apply ICAS values for general SSB and low duty cycle CW use.

Apply CCS values for contest style SSB, high duty cycle CW, RTTY and FT8 use.

Remark: Our products are labelled with worst case (CCS) values.

Why do I need a kilowatt + rated BALUN? I’m never running more than 200 Watts

Antennas and consequently also the BALUNs attached to them, are very frequently subjected to high voltage surges, caused by induction due to lightning or static charges. The levels of these surge voltages are many times higher than the normal working RF voltages applied during transmission.

As a result, the insulation of low power BALUNs is continuously stressed, potentially resulting in microscopic burn holes in the dielectric insulation of the windings. These micro burns often do not lead to immediate catastrophic failures, but cause a considerable lifetime shortening of the parts. They degrade much faster, eventually causing a short circuit or arcing fault.

High power rated BALUNs use windings with much higher voltage withstand properties than of the shelf low power amateur products. As a result, they can withstand considerably higher surge voltages, and do not suffer degradation over time.

So, for sure, it makes sense to use high power rated BALUNs, even if you’re running low power only.

Correct use of RF GURU ANTENNA TUNER BALUNs

Unlike standard baluns, ANTENNA TUNER BALUNs are deployed in a heavily mismatched impedance environment. Consequently, special attention must be paid to their correct application.

RF GURU ANTENNA TUNER BALUNs are current baluns. These work according to the Common-Mode Choke (Current Transformer) principle. Current BALUNs have the advantage of having excellent current balancing (Common-Mode Current Rejection) properties over a wide frequency range. Using ferrite cores, baluns with a reasonable power rating can be built in a compact housing.

Current Baluns however have their limitations. Current transformers don’t like open circuits or very high load impedances at their antenna terminals.

Even with power levels of 100 Watts or less, with one, or both terminals left open (e.g. with broken transmission line wires) or when using antennas with a very high feedpoint impedance, the ferrite core can heat up, causing thermal runaway, and eventually resulting in an overheated or broken core. Therefore, when designing an antenna (e.g. doublet fed with symmetrical transmission line) the user should be aware of the impedance values presented at the antenna terminals . These impedance values vary widely depending on the used frequencies (bands).

These widely varying impedances at the antenna terminals, are in turn transformed to yet other values at the feedpoint end of the symmetrical transmission line. This is dependant on the length and the impedance of the feedline.

Knowledge of the impedance values is important, in order to determine operating conditions which are safe for the balun (and TUNER). Therefore, the user should, measure or simulate the load impedance presented at the balun terminals, at the different wanted frequencies or bands.

As a rule of thumb, when deploying doublet antennas, impedances in excess of some 500 - 600 Ohms at the balun terminals must be avoided at all times. Some tuners will probably be able to tune it, but the balun won’t like it.

For those who prefer not to calculate or simulate, or who are in doubt, it’s advised to simply use the antenna lengths and transmission line dimensions of a classic G5RV or ZS6BKW type of antenna and place the antenna tuner with BALUN at the ladderline input. This will yield very manageable and easy tunable impedance values at the HAM bands the antenna is designed for.

Furthermore, during transmission, the VSWR value should be continuously monitored. An unstable VSWR, (e.g. VSWR rising during transmission), or an automatic antenna tuner, continuously re-adjusting during transmission, are indications of the balun’s core heating up. In such case, transmission should be stopped immediately and the impedance at the end of the transmission line should be verified, and if needed antenna and/or transmission line length should be modified.

Reducing RF noise in the radio environment

RF noise (as received on an antenna system and considered annoying) consists of different contributions. There is radiated noise (noise directly incident to the antenna) and conducted noise (noise transported in a conducted way over cables). Both are present, but either of them can be dominant. Radiated noise consists of atmospheric noise (depending on atmospheric conditions) and man-made noise radiated directly from all possible appliances and digital equipment. Conducted noise mostly consists of all kind of disturbances originated in the receiver vicinity and brought into the weak signal wanted signal path by conduction over cables an penetration into it, e.g. directly due to shielding effectiveness limitation or by Common Mode to Differential Mode conversion. Radiated noise can convert into conducted noise, and conducted noise can convert into radiated noise. Radiated noise or interference can only be lowered by eliminating the source of noise, or by increasing the distance to the disturber. (Remember that the field strength lowers by the square of the distance). Conducted noise can be effectively lowered by inserting choking in the unwanted cable paths. Conducted noise issues are experienced during reception (increased noise floor) as well as during transmission (RF feedback disturbing the radio). RF feedback into the radio transceiver during transmission is a typical example of conducted interference.

The first cause of conducted interference is often a non ideal transition of symmetrical to a-symmetrical media. This mainly occurs at the antenna feed point. At that point differential mode signal (the RF signal transmitted) is converted into unwanted common mode signal (the sheath current flowing on the outer surface of the coaxial cable) and the common mode (the noise current present on the outside of the coaxial cables during reception) is converted to differential mode signal adding up with the wanted low signal. So the use of BALUNs with a good common-mode rejection is the first thing to be considered. Next, a low impedance “clean” grounding of the coaxial cable outer shielding on the antenna side is considered good practice. Together with adequate choking it adds a “second order” to the Common-Mode filtering. The safety ground (and wiring) of a house electricity installation is intended for safety purposes and has too high a impedance at RF frequencies to be able to drain RF noise to ground so it is “polluted” with RF interference originating in all equipment connected to it.

A clean RF ground consists of several ground rods interconnected with heavy gauge earthing cables placed some distance (e.g. 10m mimimum) away from the polluted safety grounding so that RF noise cannot couple into it via coupling through earth. It can also serve as antenna or tower primary lightning protection. The clean RF ground needs to be isolated by all means from the polluted safety ground by installing common-mode chokes (line isolators in coaxial cables and chokes in earth bonding wires and control cables) between them. Station equipment (e.g. transceiver, RF amplifier and antenna tuner) needs to be bonded together as to for one common apparatus. (Use an earthing bar or the heaviest and shortest possible earth interconnection wires or straps). Do not install ferrite cores or sleeves on those earth bonding interconnections. Ferrite chokes can be installed on interface cabling between individual equipment (e.g. on control and communication wiring). There it makes sense. Even though electrical safety ground is not RF clean, station equipment needs to be connected to safety ground obviously for electrical safety reasons. As long as the shielding integrity of the radio equipment and cabling shielding effectiveness is good enough this does not harm its noise behavior. The common-mode disturbances stay on the outside of the shielding enclosures. However, as stated before, care should be taken that this common-mode noise does not convert into differential mode noise and couple into the weak signal wanted signal path.

Therefore, use coaxial cables with the best possible shielding effectiveness and pay attention to coaxial connector shielding connections. Coaxial line isolators and RF chokes on the cables leaving the shack or house are an additional means of protection. Attempts to lower the RF impedance of the electricity safety ground mesh, by adding ground rods right at the shack position can be of help, as long as they are not too close to the clean RF grounding system, however, often this is not the perfect solution. Isolating the clean RF ground and the safety ground by means of common-mode chokes often yields the best results. Remember that, as a rule of thumb, a straight wire or cable (e.g. grounding cable) has an inductance of in the order of 1 nH per mm, meaning that 1m of grounding cable can easily have an impedance of 20 ohms or more on 3 MHz and 200 ohms or more at 30 MHz. (This is not to be considered as a low impedance to ground).

Placing an additional mains filter into the incoming shack AC mains cabling can be helpful to supplement the mains filter in the equipment. A dedicated additional mains filter in the mains circuit of typical equipment knowing to cause interference like those with a switched mode power supply can also be considered but need to be evaluated on a case-by-case basis. If mains filtering is deployed, additional ferrite core common-mode choking is an overkill as mains filters already include adequate common-mode filtering.

Mounting flanged enclosure on Boom, Mast or Support Tube

RF GURU BALUNs and LINE ISOLATORs are built in enclosures with flanges, containing mounting holes. So they can be installed on any surface in an easy way, using screws or bolts.

In order to install them on a boom of a beam, or on a support tube or mast, the user can make a suitable mounting plate with brackets, hose clamps or hydraulic clamps. (Hydraulic clamps (So called “Stauff” clamps) with a 2 inch bolt center-to-center distance are a perfect solution).

Alternatively cable ties can be used, following the next steps: Use 5mm x 400 mm (or longer) weather and UV resistant cable ties.

Insert the cable tie trough the enclosure holes as shown in the following picture:

Mount on boom or mast as follows:

Tighten cable tie with pliers

All set!

BALUN: What it is and what it’s supposed to do?

The word BALIN means "BALANCED TO UNBALANCED", but a lot of HAM Radio users have no idea what a BALIN is or what it is supposed to do. This article attempts to explain.

A little bit of history In 1944 Geanelli Guanella invented a 16:1 matching transformer using coiled transmission lines. This effort resulted in the 1:1 and 4:1 current BALUNs we use today. In 1959 C.L. Ruthroff introduced the 1:1, 4:1, UNUN and the hybrid transformer. Ruthroff's BALUNS are known today as voltage type BALUNS. It was not until 1964 that Richard Turrin (W2IMU) presented the BALUN to HAM radio. Turrin, a co-worker of Ruthroff at Bell Labs, experimented with ferrite cores and larger wire and came up with the first high power 1:1 amateur BALUN. In 1983 Walt Maxwell (W2DU) published an article on his 1:1 choke BALUN and totally revolutionized the BALUN industry. The high power “loaded coax” common-mode choke BALUN was born.

What is it supposed to do? First and foremost a BALUN provides a smooth transition between the unbalanced feedline and the balanced antenna. Transition meaning isolation. Without a BALUN, the feedline will try to become part of the antenna, this causes a variety of problems.

Have you ever put up a dipole and had to cut the length much shorter than the formula? If so, your feedline was part of the antenna. Unwanted coax radiation is caused by a gremlin known as common mode current (CMC). CMC is a current that flows on the outside of coaxial cable and is caused by an imbalance at the feedpoint. Any dipole antenna that is constructed without the use of a well made BALUN will exhibit CMC, the extent of this phenomenon depends on surrounding structures and type of earth under the antenna. CMC causes TFI, RFI, erroneous SWR and meter readings, RF in the shack and coax length effecting SWR readings. Current should flow on the inside of coax not the outside, unless the antenna is designed as such.

Current BALUN or Voltage BALUN? Controlled radiation antennas need a current BALUN, these installations typically include half wave dipoles, verticals and windom type antennas. High power or severe duty applications also require a current BALUN.

The voltage BALUN will find very limited use in today’s modern world, after all, the voltage BALUN is the reason that BALUNs have had such a bad name in the past thirty years. Voltage BALUNs provide very little in isolation, most are very lightly constructed and are not forgiving to abuse.

BALUN construction A well made BALUN is constructed using teflon insulation, low permeability ferrite cores, stainless hardware and heavy wall UV resistant enclosures. A BALUN worthy of hanging up should be able to withstand considerable abuse year after year without giving up. The very best BALUN will be built using the diminishing current technique with multiple cores if needed, to reduce loss and heating under less than ideal conditions.

Scenarios where you could use an RF GURU BALUN

Do you recognize yourself in the following scenarios?

Installed a new antenna on the tower. After some time began experiencing a bad and unstable VSWR. I suspected a defective antenna. After investigation, my BALUN showed to have caught water, being the reason of the problem.

Not with an RF GURU BALUN. Our BALUNs are waterproof and all-weather resistant. They are IP64 provided with vent holes.

Bought a linear amplifier capable of supplying 1000 Watts. My antenna and my commercial BALUN are rated 2000 Watts. After some time, my amplifier switched into protection. Investigation showed, my VSWR had become high. I had to take down my antenna. The windings of my balun appeared to have arced and were burned.

Not with an RF GURU BALUN. Our BALUNs are rated very conservatively and are constructed using Teflon type wiring, that does not burn or melt. They are also treated with a synthetic resin, especially intended for RF applications, and rated 250 kV/cm.

Wanted to experiment with antennas. Therefore I had to loosen the connections of my BALUN several times. During unscrewing of the nuts, the internal connections released. Could not retighten them in a secure matter and now I am frightened about potential bad contacts.

Not with an RF GURU BALUN. All terminals are firmly embedded in the hardened potting material and do not loosen during manipulation of the external connections.

Due to my antenna dangling in the wind, something has loosened inside my BALUN. I hear a clattering sound inside the housing. My VSWR gets high intermittently.

Not with an RF GURU BALUN. All parts are stabilized because they’re embedded in the hardened resin.

I have installed a new antenna. As recommended, I installed a BALUN. Nevertheless I am suffering from RF Interference.

Not with an RF GURU BALUN. Our BALUNs uniquely work according the current forcing current BALUN principle, and assure the minimization of RF currents flowing on the outside of the coaxial cable shield preventing it from radiation. Furthermore they ensure an optimal antenna radiation pattern.

I was told an antenna radiates equally well without deploying a BALUN. In order to save some money, I omitted it. Now I’m experiencing an RF “hot” transceiver chassis, and I burn myself when touching my tabletop microphone’s metal parts.

This won’t happen provided you install an RF GURU BALUN current BALUN.

My shack is installed at the first floor, and I fail to adequately RF earth my radio equipment. According to good engineering practice, I installed a current BALUN, but I still experience RF interference and RF feedback.

An additional Line Isolator at the tower base or at the cable entrance will solve the issue. Combined with RF earthing of the coaxial cable outer shield this forms a highly efficient second order filter for common-mode currents.

I’m experiencing high receive signal noise levels.

The Common-Mode Choke impedance of RF GURU current BALUNs and Line Isolators is high enough to considerably suppress conducted noise from returning to the antenna over the outer shield of the transmission line, and entering the receive signal path.

To keep in mind

• When you directly feed a symmetrical antenna with a coaxial cable, there is a good chance that you experience problems with common-mode currents. Common-mode currents (sheath currents) flow on the outside of the outer shielding of the coaxial cable. During transmission these unwanted currents cause interference (RF ingress and feedback) anywhere along the path of the coaxial cable; during reception they couple noise into the wanted signal path. Furthermore, the radiation pattern of the antenna is disturbed. The Front-to-Back ratio can be considerable reduced. It behaves like you would superimpose the pattern of a random omnidirectional antenna to your directional pattern.
• A voltage type BALUN in the feedpoint only solves the problem when the antenna is perfectly symmetrical (Which is seldom the case). A current BALUN always works. It acts according to the “Current Forcing” principle.
• A current BALUN can be considered “adequately working”, as soon as common-mode choke values reach 1000 Ohms (More is better). For power levels in excess of 1000 watts, the CMC impedance value definitely needs to be higher.
• Coiled coax cable current BALUNs are much more narrow-banded than ferrite core based BALUNs, and are much more subject to detuning by environmental effects. A single ferrite sleeve, or even a few of them, have no effect on the HF frequencies (only on VHF/UHF). Only from about 10 sleeves on, some choking or balancing effect is noticeable, roughly above 14 MHz. Ferrite bead or sleeve loaded coax solutions are surpassed. Often the choking impedance obtained is too low to be effective on HF (Apply on the highest HF bands and 50 MHz only). A large ferrite torroid with 10 windings of 5 / 6 mm coaxial cable reaches the same choke impedance as 10² (or 100 ! ) single sleeves of the same permeability. This would equal some 2 meters or more of coaxial cable stuffed with sleeves (heavy and large).
• Common-mode type current BALUNs or line isolators can be considered as RX noise reducing when their value rises above roughly 2000 – 3000 Ohms (more = better).
• The imaginary part of the common-mode impedance of a current BALUN can be cancelled (to some extent) by a complementary common-mode impedance of the coaxial cable connected. This depends on the cable length and some environmental variables. For that reason it is very important that the resistive part of the impedance is as large as possible.
• When a current BALUN at the antenna feedpoint alone is not sufficient to remove all common-mode current effects, a line isolator can be added. This device is preferably installed at the base of the tower, or at the entrance of the house, near the ground and with 1 side connected to a good clean RF earth.
• Antennas (e.g. verticals) with an un-symmetrical feedpoint can also benefit from an UNUN line isolator. Here the line isolator prevents the coax from acting as a radial, thus potentially feeding RF back to the radio room. Other (non coaxial) cables installed near the antenna (rotator or remote antenna switch control cables) can pick up common mode currents and feed them back to the shack as well. These cables should be choked by ferrites too.
• Iron powder cores are not suitable for construction of CMC based BALUNs, ferrite is.
• Not all ferrite is equal. We can distinguish ferrite materials for the lower HF bands, for the general HF spectrum or for the VHF/UHF spectrum. Beware of counterfeit ferrite materials.

Optimum Common-Mode RF current and noise elimination

Figure 1

Figure 1 above shows an optimal horizontal antenna set-up, with its cabling path between antenna (left) and transceiver (right). The blocks depicted in the figures play an important role in removal of annoying unwanted common-mode currents.

Horizontal antenna (Beam, rotary dipole, wire dipole etc.) set-up

The green block (BAL) represents the BALUN. This network ensures smooth transition between the symmetric antenna and the a-symmetric coaxial cable. It ensures that, during transmission no current returns to ground over the outer surface of the coaxial cable, and during reception, no common-mode noise current originated in the house or environment penetrates into the wanted low signal path. A good quality (Common-Mode Choke type) current BALUN is recommended here.

The yellow blocks (LI1 – LI3) represent the LINE ISOLATORS. These networks remove any residual common-mode currents that may exist on the coaxial transmission line.

LI 1 is typically installed at the tower base or immediately underneath the wire antenna, close to ground, where it can be connected with the shortest and largest section possible wire to a good RF ground. Basically this Line Isolator removes most of the residual common-mode currents induced in the coaxial cable, routed in the “near-field” of the antennas.

LI 2 is typically installed in long coaxial cable runs, and serves the same function as LI 1 and LI 3. It’s deployment is optional, and depending on the particular situation.

LI 3 is typically installed where the cables enter the house or shack. It is the most interesting place to install a Line Isolator, since it separates the noise polluted safety ground connected to the TRX, from the “clean” RF ground connected on the antenna side. (The line Isolator is to oriented so that the “clean” RF ground side is at the antenna side).

Remark: LI 1, LI 2 and LI 3 are often given different names, because they are deployed at different positions of the transmission line, but electronically they are exactly the same devices: coaxial common-mode chokes with high impedance at the frequency of interest.

The blue block (TRX) represents the RADIO. Typically the transceiver is connected via its power supply to the safety ground of the house electrical installation. This ground is effective for protection of the equipment against electrical hazards, but has an RF impedance which is far too high to be useful for draining RF common-mode currents or noise. It can be improved by installing a local low impedance RF ground close to the radio equipment or if impossible due to the location of the radio’s, one can rely on the RF grounding of the Line Isolator(s) further down the transmission line path.

Figure 2

Figure 2 above shows an optimal vertical antenna set-up, with its cabling path between antenna (left) and transceiver (right).

The blocks depicted in the figures play an important role in removal of annoying unwanted common-mode currents.

Vertical antenna (Shortened (Loaded) or fill size monopole, inverted L, etc.) set-up

The green block (ZM) represents the Impedance MATCHING circuit.

Verticals installed above a good ground plane are excellent low angle radiators and as such, very suitable for working DX. This is especially true at the low HF bands where horizontals often become impractical. Often however, loading techniques need to be applied, in order to achieve practical heights. Loading verticals, lowers their feed point impedance to values that can easily get below 25 Ohms. In such cases, some sort of matching needs to be applied in order to achieve a reasonable VSWR value. This matching circuit can be a narrowband L / C network or a wideband UNUN impedance matching transformer.

Similar like in the horizontal antenna set-up, the yellow blocks (LI1 – LI3) represent the LINE ISOLATORS. These networks remove any residual common-mode currents that may exist on the coaxial transmission line.

LI 1 is typically installed immediately after the impedance matching circuit, near the vertical, and close to ground, where it can be connected with the shortest and largest section possible wire to a good RF ground. Basically this Line Isolator ensures that the vertical doesn’t “see” the coaxial outer braid as a radial and thus blocks the majority of common-mode current potentially flowing back to the radio and causing interference during transmission. Similarly, it blocks Common-Mode noise and disturbances, potentially coupling in the wanted signal path during reception.

LI 2 is typically installed in long coaxial cable runs, and serves the same function as LI 1 and LI 3. It’s deployment is optional, and depending on the particular situation.

LI 3 is typically installed where the cables enter the house or shack. It is the most interesting place to install a Line Isolator, since it separates the noise polluted safety ground connected to the TRX, from the “clean” RF ground connected on the antenna side. (The line Isolator is to oriented so that the “clean” RF ground side is at the antenna side).

Remark: LI 1, LI 2 and LI 3 are often given different names, because they are deployed at different positions along the transmission line, but electronically they are exactly the same devices: coaxial common-mode chokes with high impedance at the frequency of interest.

The blue block (TRX) represents the RADIO. Typically the transceiver is connected via its power supply to the safety ground of the house electrical installation. This ground is effective for protection of the equipment against electrical hazards, but has an RF impedance which is far too high to be useful for draining RF common-mode current or noise. It can be improved by installing a local low impedance RF ground close to the radio equipment or if impractical due to the location of the radio’s, one can rely on the RF grounding of the Line Isolator(s) further down the transmission line path.

General Remarks An RF GROUND (RF GND) is not the same as a safety ground A safety ground must have a low resistance at the mains frequency (50 Hz or 60 Hz) in order to protect electronic equipment from shock hazards, due to leakage possible currents in fault conditions. An RF ground however must also have a low impedance at the RF frequencies of interest. This can only be accomplished by interconnecting multiple ground rods, spaced apart and connected with a short large section cable to the antenna and /or transmission line set-up.

Do not forget that Common-Mode RF feedback and noise can also flow over antenna rotor cable and control cables. These cables (located in the antenna near field on one side and the radio room on the other side) should also be provided with Wideband Common-Mode Chokes to obtain an optimum result.

Polycarbonate enclosures

Our BALUNs and Line Isolators are built in polycarbonate material housings.

Polycarbonate has a number of interesting properties, making it more suitable for outdoor use than the popular ABS material.

Polycarbonate is an amorfic thermoplastic product, that, because of its excellent heat resistant and physical properties makes it very a very suitable material for rugged enclosures. It is resistant to highly fluctuating temperatures and it’s good electrical properties remain unaffected by moisture. Polycarbonate is self extinguishing , resistant to several chemical agents and has a good UV resistance; additional external coating is not required.

The enclosures used by RF GURU are designed to comply with different international recognized standards. They withstand several years of exposure to rough climatic circumstances, as needed when deployed outdoor, installed at an antenna. Moreover, they are tamper proof, which ensures they don’t break when falling or bumping against objects under windy weather.

Initially the enclosures are IP68 complying, given the different connector holes, the end product is rated IP64.

Stainless Steel Type 316

Stainless steel type 316 contains 2% molybdenum, making the material more resistant to crevice and stress corrosion and pitting corrosion. For outdoor applications or applications where the material may come into contact with chlorines or other acids, stainless steel type 316 is recommended.