Alfonso Faustino (K6ASF): Motorola XPR 7550e: BNC Female Antenna Adapter (Connector)

My team WD6DZS (engineer), NX6E (engineer), KC6YDH and I (K6ASF) created a Motorola XPR 7550(e) BNC Female Antenna Adapter (Connector) for the Motorola XPR 7550e, Motorola XPR 7550, Motorola XPR 7580, and the Motorola XPR 7580e hand-held transceivers.

Our Motorola XPR 7550(e) BNC female antenna adapter (connector):

– fits and works with Motorola XPR 7550, Motorola XPR 7550e, Motorola XPR 7580, and Motorola XPR 7580e hand-held transceivers,

– matches the polarity of all Motorola XPR 75xx transceivers,

– has an RF ground,

– does not use nor interfere with the accessory port contacts — in other words, you can still use an external speaker mic or any other accessory using the accessory port,

– is non instrusive — meaning, it is not a permanent attachment,

– does NOT void your Motorola XPR 75xx’s warranty,

– allows you to use your OEM Motorola rubber-duck antenna,

– uses the same type of bolt as the OEM Motorola rubber-duck antenna,

– has been tested by a certified Motorola technician,using an Aeroflex testing device, before and after the antenna connection, and the test results show that our Morotola XPR XPR 7550(e) BNC female antenna adapter (connector) does not interfere with the RF specifications of the Motorola XPR 7550(e) and Motorola XPR 7580(e),

– maintained the power output of Motorola specifications for both the Motorola XPR 7550(e) and Motorola XPR, 7580(e), per the Aeroflex test results; and,

– allows owners of the Motorola XPR 7550(e) and Motorola XPR 7580(e) to use antennas having coax, such as, but not limited to, car-mounted antennas and roof-top antennas.

The cost is $25 USD with a 30-day no-hassle return policy.

(Legal Stuff: Use our Motorola XPR 7550(e) BNC Female Antenna Adapter (Connector) at your own risk. We are not responsible for any damages to your Motorola XPR 75xx transceiver, as a result of using our Motorola XPR 7550(e) BNC Female Antenna Adapter (Connector). We have done extensive testing on ourMotorola XPR 7550(e) BNC Female Antenna Adapter (Connector), and none of our antenna adapters have damaged my own personal Motorola XPR transceivers to present.)

(Note: Our Motorola XPR 7550(e) BNC Female Antenna Adapter (Connector) have not been tested to the Motorola XPR 75XX’s water resistant rating; hence, when using ourMotorola XPR 7550(e) BNC Female Antenna Adapter (Connector), your Motorola XPR 75xx will not meet its water resistant rating; so, remember this NOTE if you find yourself in areas of water content and act accordingly — do not expose your Motorola XPR 75xx transceivers to water when using our Motorola XPR 7550(e) BNC Female Antenna Adapter (Connector).)

In the picture below, I was reviewing the RSSI with the Diamond SRH320A hooked up to my Motorola XPR 7550e UHF, via our Motorola XPR 7550(e) BNC Female Antenna Adapter (Connector). I was hitting an analog repeater in San Francisco called, CARLA System 2, which is within two ground miles east of location, Eagle’s Nest. I was in my bedroom.

If I want to use my standard OEM Motorola antenna, I just unscrew the Motorola XPR 7550(e) BNC Female Antenna Adapter (Connector), and I screw in my OEM Motorola rubber-duck antenna, like this stubby, shown below, to my Motorola XPR 7550e UHF transceiver.

In the picture below, I used my Motorola XPR 7550(e) BNC Female Antenna Adapter (Connector) with a coax that is connected to my car-mounted antenna.

Our Motorola XPR 7550(e) BNC Female Antenna Adapter (Connector) has an RF ground to shield the coax — that way, our Motorola XPR 7550(e) BNC Female Antenna Adapter (Connector) doesn’t use the coax as an extension of the antenna; but, rather, our RF grounded Motorola XPR 7550(e) BNC Female Antenna Adapter (Connector) keeps the coax functioning as a tunnel to transmit and receive RF from and to the external antenna and to the transceiver, as the way the coax was designed to do.

In the video, below, I’m hitting a DMR repeater that is ~60 ground miles south of my parked location.  My Motorola XPR 7550e is using our Motorola XPR 7550(e) BNC Female External Antenna Adapter (Connector) connected to the coax of my car-mounted antenna, which is the Browning BR-137 Tri-Band High Gain Antenna:

In the picture, below, I’m hitting the analog WIN System repeater in Napa, CA, while mobile in San Francisco, CA. I’m using my Motorola XPR 7550e, with my Motorola XPR 7550e BNC Female Antenna Adapter (Connector) connected to a coax that leads out to my car-mounted antenna. The distance between me and the Napa repeater is ~55-65 ground miles north of San Francisco, CA.

Now, with my Motorola XPR 7550(e) BNC Female Antenna Adapter (Connector) I can use my Motorola XPR 7550e UHF when I’m in my car hooked up to the coax of my magnetic car-mounted antenna and increase the RF range of my Motorola XPR 7550e, Motorola XPR 7550, and my Motorola XPR 7580.

In the picture below, I hooked up my Motorola XPR 7550e to my rooftop antenna, Diamond x50, and I was reviewing the RSSI with my Motorola XPR 7550(e) BNC Female Antenna Adapter (Connector). I was hitting CARLA System 16, which is located in Sacramento, California, which is ~ 70 ground miles Northeast of my location, Eagle’s Nest.  It is an analog repeater.

Email me for orders or questions: K6ASF@Yahoo.com.

In the picture below, I was using my Motorola XPR 7550 BNC Female Antenna Adapter (Connector) with my Motorola XPR 7550 VHF transceiver. I was connected to the coax of my external roof-mounted antenna, Diamond X50, and I hit an analog  repeater, K6BW, which is located in San Anselmo, CA.. I was talking to the owner of the repeater, and he was impressed with my transmission qualities. San Anselmo repeater is ~ 47 ground miles North of Eagle’s Nest.

In the picture, below, I’m using the Diamond SRH320A with my Motorola XPR 7550e connected to my Motorola XPR 7550e BNC Antenna Adapter (Connector), hitting a Napa, CA analog repeater that is ~60-70 ground miles north of Eagle’s Nest.

The RSSI in the picture, supra, reads, “-97.387.”

Pretty impressive given my location, as seen in the map, supra, being indoors, and using a non OEM Motorola rubber-duck antenna.

Here is a video of a WIN System Moderator, WB6IAG, communicating with a HAM operator.  The WIN System Analog Repeater, in the video, below, is located in Napa, CA, which is ~60-70 ground miles from my home-base, Eagle’s Nest.  I’m using my Motorola XPR 7550e, with my Motorola XPR 7550e BNC Female Antenna Adapter (Connector), connected to my Diamond SRH320A non OEM Motorola rubber-duck.  The RSSI reads ~91-94 dBm.

In this video, below, our Motorola XPR 7550 BNC Female Antenna Adapter (Connector) is in action, using the Diamond X-50, coax roof-top antenna, on VHF analog simplex frequency with my Motorola XPR 7550, listening to firefighters working on the Kincade fire up north in Shiloh, CA, from my home-base, Eagle’s Nest, which is ~60-75 ground miles away.  Remember, this is SIMPLEX, not repeater-mode.

I’m very pleased with our creation of the Motorola XPR 7550(e) BNC Antenna Adapter (Connector) for the Motorola XPR 7550, Motorola XPR 7550(e), Motorola XPR 7580, and the Motorola XPR 7580(e) hand-held transceivers; and, I hope you will be, too.

Check6!

/s/ Alfonso Faustino (K6ASF)

Craftmanship Of Our Motorola XPR 7550e, Motorola XPR 7550, Motorola XPR 7580, and Motorola XPR 7580 BNC Female Antenna Adapter (Connector)

Our Motorola XPR 7550(e) BNC Female Antenna Adapters (Connector) for the Motorola XPR 7550, Motorola XPR 7550e, Motorola XPR 7580, and Motorola 7580(e) transceivers are made in the United States.  We assemble the adapters by hand using quality materials.

By the way, should you decide to make your own, get it tested by an authorized Motorola technician using an Aeroflex testing device…oh, my Motorola technician charges $125/hour per transceiver.  I have three transceivers that I tested with our Motorola XPR 7550(e) BNC Female Antenna Adapters (Connector) — you do the math.

The testing cost is irrelevant to me…as long as I know our Motorola XPR 7550(e) BNC Female Antenna Adapters (Connector) does not interfere with the Motorola XPR 7550, Motorola XPR 7550e, Motorola XPR 7580, and Motorola 7580(e)’s RF specifications, then I’m happy and confident to put our Motorola XPR 7550(e) BNC Female Antenna Adapters (Connector) out to market.

Many people tell me they can get the same product on eBay for $2 to $5…I tell them, “go right ahead.” I am certain if you buy it on eBay or elsewhere online or at a store, the product has not been tested nor be the correct adapter (connector) for your Motorola XPR transceiver.

How do I know this?

Because, in my desperation for wanting this type of connector and being tired of waiting for someone to create this type of connector, I made purchases on eBay and elsewhere HOPING the products I purchased would work on my Motorola XPR 7550, Motorola XPR 7550e, and Motorola 7580…of course, the connectors I purchased from eBay and elsewhere did not properly match the specifications for the Motorola XPRs.

In addition, the bolts used by other manufacturers were not the proper bolt nor properly sized to fit into the antenna housing of the Motorola XPR 7550 and Motorola XPR 7580 transceivers.

To make one Motorola XPR BNC Female Antenna Adapter (Connector), it takes us about 40 minutes to assemble and properly size our adapters to the Motorola XPR 7550 and Motorola 7580 transceivers.

How did we get the exact specifications for the Motorola XPR transceiver?

We took apart one of my Motorola XPRs and studied the body and the circuit board.

We then took our understanding of the Motorola XPR and applied it to the design and build of our Motorola XPR BNC Female Antenna Adapter (Connector).

The materials we use are high-quality — especially, the antenna bolt.  The antenna bolt is difficult to find; because, it MUST match the polarity of the Motorola XPR — if it doesn’t match the polarity of the Motorola XPR transceiver, you will not get a good RX and TX; and, furthermore, you might cause damage to the capacitors in the Motorola XPR transceivers.

The bolt has a specific name.

Since the Motorola XPR 7550(e) and Motorola XPR 7580(e) transceivers were purposely designed not to accommodate non OEM antennas, we had to apply our RF engineering knowledge into the build of our Motorola XPR 7550(e) BNC Female Antenna Adapters (Connectors)…this led to the creation or the RF ground designed to our antenna adapters for use with a coax.

Without the RF ground, the coax would act as part of the antenna; and, the purpose of the coax is NOT to act as part of the antenna; rather, the coax acts as a tunnel to receive and transmit RF to and from the Motorola XPR 7550(e) transceivers and to and from the car-mounted or external antennas.

Not having an RF ground for the coax would impede the Motorola XPR RF specifications.

Our RF ground to our Motorola XPR 7550(e) BNC Female Antenna Adapters (Connectors) meets the Motorola XPR 7550(e) and Motorola XPR 7580(e) transceivers’ RF specifications when hooked up to a coax.

It is my opinion, Motorola wanted to increase sales to their mobile transceivers, such as the Motorola XPR 5550.  In order to increase sales, they removed the SMA pin, which was found in their preceding model, Motorola XPR 6550, and moved the SMA pin into the OEM Motorola antenna.

By doing this, customers would be forced to purchase the mobile units instead of connecting their hand-held Motorola XPR 7550(e) and Motorola XPR 7580(e) transceivers to the coax of their car-mounted external antenna or an external roof-mounted antenna.

The Motorola XPR 6550, which is now discontinued and replaced with the Motorola XPR 7550(e), was the last hand-held transceiver that had the SMA pin built into the Motorola XPR 6550’s body; hence, many owners of this model enjoyed the freedom of expanding the range of their Motorola XPR 6550 transceivers with the use of a car-mounted or roof-top antenna.  Because of this, there was no need for an operator to purchase Motorola’s mobile units, such as the Motorola XPR 5550 transceivers.

After many hours of engineering theory, material studies, and industrial design, we came up with our Motorola XPR 7550(e) BNC Female Antenna Adapter (Connector) that meets the Motorola XPR 7550, Motorola XPR 7550e, Motorola XPR 7580, and the Motorola XPR 7580e’s RF and power output specifications.

Sure, it looks like the stuff you can get on eBay or elsewhere; but, believe me…it is nothing like the stuff you see on eBay or elsewhere.

Before putting the Motorola XPR 7550(e) BNC Female Antenna Adapter (Connector) out to market, we had to test it.  Two of my team-mates are experienced engineers and have engineering degrees; they have many years of experiences in RF and microwave engineering; hence, they have extensive equipment to put our Motorola XPR 7550(e) BNC Female Antenna Adapter (Connector) to the test…my Motorola XPR 7550e (UHF), Motorola XPR 7550 (VHF), and my Motorola XPR 7580 (800-900 mHZ) were the test subjects.

We tested theMotorola XPR 7550(e) BNC Female Antenna Adapter (Connector) with dummy loads, various external antennas, various lengths of coax, many different rubber-duck antennas, and so on.  We also tested our Motorola XPR 7550(e) BNC Female Antenna Adapter (Connector) through hours of analog and DMR use.  It passed our test parameters — no interference with Motorola XPR 7550, Motorola XPR 7550e, and Motorola XPR 7580’s RF and power specifications; and, most importantly, no over-heating — all the transceivers stayed cool — great news; because, heat is one of the signs of problems when using a bad antenna or mis-matched antenna.

After conducting our tests, we had to make sure our numbers and test results were accurate; so, we brought our first Motorola XPR 7550(e) BNC Female Antenna Adapter (Connector) and my transceivers to an authorize Motorola dealer and technician. The technician hooked up my transceivers with our Motorola XPR 7550(e) BNC Female Antenna Adapter (Connector), and he tested the transceivers and our first adapter before and after the antenna connection with an Aeroflex testing and tuning machine; and, our first Motorola XPR 7550(e) BNC Female Antenna Adapter (Connector) with the RF ground passed — no congestion, no spill-back, no over-heating, and not interference with Motorola XPR 7550, Motorola XPR 7550e, and Motorola XPR 7580’s RF and power performance specifications.

By this time, about two months had passed, and we were finally able to introduce our Motorola XPR 7550(e) BNC Female Antenna Adapter (Connector) to our HAM network in the San Francisco Bay Area.

Our first sale, went to the president of the San Francisco Radio Club; our second sale went to a HAM operator in Massachusetts, and, other sales went to international HAM operators.

We now have a back-log; and, new orders won’t be available until the end of October 2019.

Since we are a small operation, we have to assemble our Motorola XPR 7550(e) BNC Female Antenna Adapter (Connector) by hand; and, after being assembled, each unit must be tested to ensure they meet Motorola’s RF and power specifications.  Once the Motorola XPR 7550(e) BNC Female Antenna Adapters (Connectors) pass the tests, they go through performance testing by staying on my transceivers for a full 24 hours of RX and TX use on DMR and analog.  I also test their performance connected to a coax for the second 24 hours.

After 48 hours of testing, the units are ready to be shipped out to the owner.

We are truly happy with our Motorola XPR 7550(e) BNC Female Antenna Adapters (Connectors). The benefits I’ve had of using our Motorola XPR 7550(e) BNC Female Antenna Adapters (Connectors) on my Motorola XPR 7550, Motorola XPR 7550e, and Motorola XPR 7580 transceivers have been invaluable; as, well as cost-effective; because, now, I don’t have to fork up money for an XPR 5550 mobile unit.

If you have any questions, feel free to contact me: K6ASF at yahoo dot com.

Oh, in case you wanted to know…below, was our first prototype, which we called, Frankenstein; because, it was built by cannibalism. We cannibalized an OEM Motorola antenna, creating an SMA pin, and using an SMA BNC antenna adapter we got from eBay.

We joined all three pieces together with solder, epoxy, and shrink insulation.

This design was ugly, and it created a structural vulnerability of breakage and damage to the Motorola XPR 7550e because for Frankenstein’s high center of gravity.

Moreover, Frankenstein failed our testing parameters — the RF numbers failed Motorola XPR 7550e’s specifications — big time!

Our present Motorola XPR 7550(e) BNC Female Antenna Adapter (Connector) for the Motorola XPR 7550, Motorola XPR 7550e, Motorola XPR 7580, and Motorola XPR 7580e transceivers have come a long way, baby; and, it definitely looks and performs better than Frankenstein — yes?

Check 6!

/s/ Alfonso Faustino (K6ASF)

2 Comments Add yours

  1. Rick Hillstead says:

    Looks good!
    I’ve been tinkering with ways to convert the lug antenna connector in my 7580 to miniUHF for mobile use with no loss in the 900mhz ham spectrum. Not an easy task as you have outlined!
    N4RAH

    Like

    1. Congrats on your results! Thanks for your post!

      Like

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