Tx rx duplexer tuning


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Instead, it uses cables to wire directly into the IO pins of the radio s you choose. They operate full duplex and have both a transmitter and a receiver in each one. I am needing to link to some other repeater sites by internet. February 5, Chris Hood. Rockstar has returned to the wild west with the release of Red Dead Redemption 2, and RDR2: Companion is the long-awaited game's official companion app. The repeater is online and serves Socorro at a frequency of Then I soldered wires to pins 13 and 48 of the CM and other pads.

I may finally be getting internet to one of my repeater sites after a long time of trying. Allstar Repeater Linking. Documents About The Amateur Repeater Linking repeater-builder. Only place a definition ; for your local nodes, and private off of allstar link nodes here. Repeater Link Stats? Allstar Active Nodes! Live DMR Audio.

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This is due to having receivers which provide a more complete coverage of our effective service area. Episode Introduction to an Allstar Node.

Also called VoIP linking protocols. ID-RP2V 1. InI began my profession by creating a hair style rather than a haircut, unlike others. I found a significant benefit to being Monograph - Allstar Newbie Guide - Repeater Builder your first allstar repeater is available in our digital library an online access to it is set as public so you can download it instantly. Substantially all repeater users have a full quieting signal into the repeater.

Note: After the repeater owner finally got his Allstar and Echolink accounts setup and a node created we changed the node to reflect his accounts. Were Is The Lightning? Input: It could as well function as Allstar-node or, of which I've seen people have constructed from the same modules. California I have to increase the PL level quite high to get it to where it decodes, then the audio gets raspy. Just as highspeed digital networks led to brand-new ways to communicate, D-STAR brings digital systems to the amateur bands to create entirely new radio systems and services.

This cannot be undone.The duplexer exhibits less than 1. Ham radio in my parts is dead on anything above MHz. I am putting emphasis into MHz equipment right now and selling off the stuff I don't use to fund my next project. It has no dents, physical blemishes or electrical abnormalities that would keep it from operating perfectly for years to come. It has been in a climate controlled, dry, clean facility for the past 6 years, since I bought it new from Tessco.

It is priced to sell, lower than others listed here because I am in need to move it quickly. Please allow three 3 business days of handling time, the time between cleared payment and the time I can ship. It will be packaged with the utmost care and consideration so it will reach you in perfect condition.

No international shipping. Please contact me with any questions you may have. The winning bidder needs to send me their frequency pair ASAP so I can get it tuned for you and have the papers printed.

Thanks much and best of 73 to all hams out there. High amount watching. Great seller with very good positive feedback and over 50 ratings. See Details on eBay available at.

PicClick Exclusive Popularity - 3 watching, 1 day on eBay. Recent Feedback. See Details.Lieske, Sr. Founder, EMR Corporation Forward A technical bulletin on this subject was prepared in Since then, antenna duplexers have continued to increase in numbers and many new designs have appeared in the marketplace. This bulletin will review antenna duplexers with emphasis on the theory of operation, methods of tuning and maintenance of them. Duplexer, Defined: The terms duplexer and diplexer have been used interchangeably for many years.

The prefix Di is defined as twice, double or twofold. The prefix Du means two or dual. Plex from the latin word plexus has, among other meanings, the definitions: An interwoven arrangement of parts; A network.

Thus we med9 immo off tool conclude that duplexer and diplexer have the same literal meaning. It is noted that duplexer has been used with regard to wireless land mobile systems and diplexer has been used in microwave system application. We will stay with duplexer to refer to the devices covered in this bulletin. Duplexer Types Figure 1 There are two basic types of duplexers, and.

The easiest one to understand is the band pass duplexer. Duplexer Applications A duplexer provides the means for simultaneous operation of a mobile relay or repeater station having separate TX and RX frequencies when using a common antenna. The benefits of this include: Saving one antenna and one transmission line, compared with using separate transmit and receive antennas for a repeater, maintaining reciprocal receiving and transmitting signal path characteristics compared with separate, TX Figure Note that each branch has three cavities connected together with cables.

A tee junction and two more cables connects the two branches with the antenna feed line. Sufficient selectivity must be provided by the cavity filters to preclude transmitter carrier power from desensitizing the relatively broad response of the receiver front end and to also reduce transmitter wide band noise to a level below the threshold of receiver sensitivity. Typical selectivity curves of the three cavity resonator groups in each duplexer branch are shown in Figure 2.

Two other curves are shown to represent the transmitter wide band noise spectrum and the desensitization free spoof text of the receiver front end. Note that each filter branch provides attenuation of signal power equal to or greater than the noise and desensitization levels. Note that each cavity has only one coupling loop. The loop has a series capacitor, which is adjustable to resonate the loop itself, providing a reject notch when adjusted to a desired frequency.

The loop also couples energy into the cavity at the desired coupling factor, producing a relatively broad pass band selectivity. The notch can be placed either above or below the resonant frequency of the cavity, as needed.

The typical performance is shown below db Transmit MHz. Transmitter wide band noise curve Receive MHz. Receiver frontend desens. Note that the pass responses are quite broad.

The overall notch depths are very sharply defined and sufficient in depth to equal or exceed the noise and carrier desense requirements. Each type has benefits and shortcomings compared with the Some of these are: Type: Generally will have higher branch loss than pass-reject type, 1. Far superior for dense site use. The multiple cavity strings provide added selectivity for the receiver and a high order of spurious and harmonic rejection for the transmitter.

Requires larger, higher Q cavities, and more of them, resulting in higher cost and need for greater site space occupancy. Through use of correct branch cable lengths and careful loop coupling adjustments, this duplexer type can be tuned for a broad nose response to accommodate multi-frequency transmitters and receivers.

Higher costs than pass notch types due to requiring larger cavities. Since pass band is broad, little help is provided in receiver front end selectivity except for the transmit carrier notch.

This can be a real problem when placed at high density sites. Can use smaller volume cavities for a given TX-RX spacing, saving space.Post by gmrs » Wed May 11, am. Post by Satelite » Fri May 13, pm. Post by gmrs » Sat Jun 25, am. Post by Wowbagger » Sat Jun 25, pm.

Post by gmrs » Sat Jun 25, pm. Post by kcbooboo » Mon Jun 27, pm. Style by Arty - phpBB 3. Privacy Terms. Batboard Batboard Forum Skip to content. Quick links. The General forum is where users can discuss any topic regarding Motorola communications equipment - hardware, software, etc. There are also several focused forums on this board, so please take the time to ensure that your questions doesn't fall into one of those categories before posting here!

I took it to a professional radio shop for tuning and they told me that sure enough, one of the band pass rods center one on the low pass side appears to be stripped. I don't know if that means that he could not tune the pass for that cavity at all, or could not get it all the way where it needed to be. When I picked it up the tech was not in so I could not talk to him to determine exactly what the impact to the tuning was.

My understanding is that on the Hi RX side the pass and reject tuning went fine, so my RX side should be fine. On the TX side the reject tuning went fine, but as I said, one of the three band pass rods was stripped.

I won't be able to put this on the repeater until this weekend to test it, but I am trying to get a feeling for the impact this will have.

The previous setpoint for the cavity in question was I believe that "all" this means is that the one cavity will not be tuned well to pass my TX freq resulting in some attenuation. I will have to see how much loss it is to determine how much of a problem it is. One thought I had is could I bypass that cavity by simply jumpering over it it is the middle cavity of the three on the low pass side?Effective date : Year of fee payment : 4.

The disclosure describes a dual hybrid duplexer including two hybrid couplers, two intra-filters, a tunable isolation load, and a phase shifter. The phase shifter may be located at the isolation port. The phase shifter may be located at the antenna port. In one embodiment, a dual hybrid duplexer includes two hybrid couplers, two intra-filters, a tunable isolation load, a first phase shifter located at the isolation port, and a second phase shifter located at the antenna port.

The first and second phase shifters have a difference of 90 degrees plus or minus 10 degrees. This disclosure is in the field of tunable duplexer architecture for multiband communications. Specifically, conventional switches and duplexers may be replaced by tunable duplexers including 90 degree hybrid couplers or including quadrature couplers.

Conventional radio cellular systems include many switches and many individual non-tunable duplexers. These components are growing in numbers and undesirably increasing the total solution cost and size. Specifically, FIG.

For the sake of clarity and conciseness, many other elements such as a diversity antenna and related circuitry are not shown in FIG. Also, the wiring for received signals exiting the duplexer is not shown. In a receive mode, signals flow from right to left. Duplexer D 17 receives the received signal VD 17and then outputs a duplexed received signal not shown. The duplexer generally performs filtering that is specific for the band in which the duplexer is operating.

The hybrid structures in FIG. These hybrids are also known as 90 degree Hybrid couplers or Quadrature Couplers. Thus, hybrid HYB 2 simultaneously provides a 3 dB power split into two signals half power to the upper right, and half power to the lower rightand a 90 degree phase shift to one of the signals to the lower right. For example, Tunable filter TF 2 may be a band pass filter centered at the transmit frequency. In one embodiment, tunable filters TF 2 and TF 4 are identical.

Now, these two half power signals have each been shifted 90 degrees, and they will add not cancel at Port 2. The second hybrid HYB 4 combines the split signals, while shifting the upper half by 90 degrees. Specifically, as discussed above, hybrid HYB 4 receives signal V 24 a half power, un-shifted, filtered, transmission signal. V 24 is transmitted directly to V 26 without any additional shifting. Additionally, hybrid HYB 4 receives signal V 25 a half power, 90 degree shifted, filtered transmission signal.

V 25 is transmitted to V 26 with an additional 90 degree shift, creating a half power, degree shifted, filtered transmission signal. Thus, V 26 combines a half powered, un-shifted, filtered transmission signal with a half power, degree shifted, filtered transmission signal, and these two signals ideally cancel out because they are equivalent in magnitude but degrees out of phase.

Thus, V 26 is near zero, illustrating very high isolation between the transmitted output VANT and any signal leaking out as VSkip to Main Content. A not-for-profit organization, IEEE is the world's largest technical professional organization dedicated to advancing technology for the benefit of humanity.

Use of this web site signifies your agreement to the terms and conditions. Thus, only a single hardware is necessary to serve all fs19 seed drills channel combinations of the overall radio frequency band - a prerequisite for large scale low cost unit production.

The applied filters consider optimal tailored transfer functions with transmission zeros, realized with compact planar overmoded TE cavity structures to accommodate the extreme rejection demands while maintaining low insertion loss.

A further design aspect has been easy integration and interfacing into the waveguide subsystem of the radio equipment. The complete duplexer structure has been designed using a mode matching based CAD. To satisfy the stability of the responses for the given outdoor environmental conditions it has been realized from silverplated INVAR sheets - a technique supporting the low cost issue.

Good agreement of computed and measured results and the successful testing of the tuning capability verifies the design. Published in: 33rd European Microwave Conference. Article :.

TX Combining Systems

Need Help?Principal Engineer Ian Graham explores a common question in radio system design: whether to deploy duplexers or to use separate transmit and receive antennas.

On the face of it, using a duplexer to reduce the number of antennas required by the system sounds like a great idea. A duplexer is a three port filtering device which allows transmitters and receivers operating at different frequencies to share the same antenna. A duplexer typically consists of two band pass filters connected in parallel. One filter provides a path between the transmitter and the antenna, the other provides a path between the antenna and the receiver.

No direct path between the transmitter and receiver exists. The obvious advantage of using a duplexer is that we can transmit and receive with only one antenna. With space on towers at base station sites at a premium, this is a real advantage. In single channel systems, where there is only one transmitter and one receiver, use of a duplexer so they can share a common antenna is a straightforward choice. However, when multi-channel systems with several combined transmit and receive channels are considered, the situation becomes more complex.

The main disadvantage of using duplexers in multichannel systems can be seen when we consider transmitter intermodulation. This is the mixing of the multiple transmit signals on the antenna. Once the transmitters are combined, any non-linearities or imperfections in the duplexer, the cabling, or mammu name images antenna itself will cause the transmit signals to mix and produce intermodulation products on the antenna side of the duplexer.

Closest to the transmitted signals are the third order products, 2F1-F2 and 2F2-F1, followed by the fifth order, seventh order products etc. Corroded connectors or damaged cables are classic causes of this effect, known as Passive Intermodulation or PIM. In the example shown, the fifteenth order 8FF2 and seventeenth order 9FF2 intermodulation products fall right on top of the receive channels. These intermodulation products go straight through the antenna to the receive path of the duplexer and in to the receivers.

If the amplitude of these intermodulation products is greater than the noise floor of the receiver, then the receiver sensitivity is degraded leading to a loss of uplink coverage. This is most likely to occur if the spacing between the transmitter channels is a sub-multiple of the transmit-to-receive frequency separation.

Wherever possible then, if you have to use a duplexer, combine transmit channels where the resulting intermodulation products do not land on a receive channel. The big advantage is that, while passive intermodulation still occurs in the same way between the combined transmitted signals, there is no longer a direct path for these products to reach the receiver. Instead, the isolation between the transmit and receive antennas provides additional protection.

If the transmitters and receivers are arranged in a co-linear fashion ie: one directly above the other, generally with the receive antenna highest up the towerthen isolations in excess of 50dB are easily achievable.

So in conclusion, for single channel systems, go ahead and use a duplexer. But for multi-channel systems, while separate antennas will cost you more space on each tower, this is the more resilient option. It protects your system better from the significant interference from passive intermodulation as a result of those very minor and difficult to isolate assembly or maintenance faults.

This article is taken from Connection Magazine, Edition 4. Connection is a collection of educational and thought-leading articles focusing on critical communications, wireless and radio technology.

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An excellent article and highlights issues that many disregard which creates issues for not only themselves but also other users at adjacent sites. I have just these issues on a site that has upwards of repeaters at a number of sites all within 1Km of each othera nightmare to say the least. I hope many more read and take notice, thanks. Your email address will not be published. This site uses both functional cookies and tracking cookies to help us understand how users interact with the site.

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Blog When and where to use a duplexer. Home Blog Thought Leadership When and where to use a duplexer. When and where to use a duplexer. What is a duplexer? Common antenna with duplexer The obvious advantage of using a duplexer is that we can transmit and receive with only one antenna. TX RX Systems Inc. reserves the right to replace with merchandise of equal performance although not Vari-Notch duplexers are originally pre-tuned at the.

As an aid to those in the field concerned with servicing Duplexers, TX RX Tune a signal generator to the receive frequency and inject it into the. This duplexer has both pass and reject properties in both sections. The Pass / Reject Duplexer can be tuned by using a return loss bridge to tune the Rx and Tx. Rack depth with cavity tuning rods at maximum frequency. TX RX Systems offers a wide variety of Duplexer options to suit your application, including.

TX/RX MHz Vari-Notch Duplexer. Four in diameter cavities. N Female connector. *Factory Tune to. VHF UHF Duplexer Cavity Filter Bandpass BpBr - TUNING Service Wacom TXRX, etc.

OPT HELLAS Duplexers are band reject type cavity filters which are designed Spacing (ΔF=Tx-Rx) MHz Specify tuning method (single or multiple chanel). Everything I read, > including the manual from TXRX states I need a spectrum analyzer for the > tuning the duplexer. Is there any other way besides buying a.

This paper proposes an adaptive RF front-end (RFFE) architecture that uses an electrical-balance duplexer (EBD) and tuned surface acoustic wave (SAW) resonators. VARI-NOTCH®, the trademark for TX RX SYSTEMS' pseudo bandpass circuit design, offers the best frequencies, these duplexers are easy to tune in the field. Understanding, Maintaining & Re-Tuning Antenna Duplexers. By William F. Lieske, Sr., Example: Originally factory tuned for TX and RX. Compact Rx/Tx Channel Duplexer with Tuning.

Capability for Integration in a 26GHz High Capacity. Short Haul Radio Equipment. Ralf Beycr', Peter Krauss'. A novel Ka-band Rx/Tx channel duplexer1 design with tuning capability is established for the 26GHz band. Thus, only a single hardware is necessary to serve.

A tunable duplexer prototype is demonstrated with TX-RX isolation better than 50 Tuning is achieved using digitally controlled switched capacitors with. Set the radio to the TX frequency and connect to the duplexers antenna connector. Set a wattmeter to the RX port and a 50 ohm load to the TX.

All of Comprod Inc. ” and 10” filters have two hand-movable tuning rods Pass-Reject Duplexer Isolation-db: TX noise suppression at RX frequency.

TX-RX SYSTEMS R1 MHz ( MHz) Duplexer Ham - FREE TUNING! - $ FOR SALE! TX-RX Systems R1 MHz ( MHz). As the frequencies get closer, a higher value of isolation is required. At high-band VHF, the TX RX Vari-Notch design is the most commonly used. Vari-Notch. Model, DPRV, DPRV. Operating Frequency band, MHz, Insertion loss (adjustable) not more, dB, 1,5, 2.

Frequency separation TX/RX (min), MHz. Four types of cavity filters are designed and manufactured by TX rX push/pull tuning (not threaded) mechanism stays on frequency when locked down.