Power Supply and Antenna Suggestion

[Danny]

I would like to setup a radio inside and looking for suggestions on a good power supply. I want something that is worth it and will last a long time. I don't mind spending over $100 for a good decent power supply. 

 

Also any suggestions for a Apartment antenna? It's where we live for now until we find a house. 

[BoxCar]

You have many options for a power supply. Get one that outputs between 12 and 15 VDC, 13.8VDC being ideal. Most allow the voltage to be adjusted so you will need a meter. The amperage should be at least 10% greater than the transmit draw of your radio. In watts, that's volts times amps. 

 

For an antenna, I would look at a J-pole or one that doesn't need a ground plane for use in your apartment. Once you get in your house, whatever you can both afford and get away with. With radio, height is king so you need your antenna as high as possible as it directly affects the range you will have.

[Danny]

You have many options for a power supply. Get one that outputs between 12 and 15 VDC, 13.8VDC being ideal. Most allow the voltage to be adjusted so you will need a meter. The amperage should be at least 10% greater than the transmit draw of your radio. In watts, that's volts times amps. 

 

For an antenna, I would look at a J-pole or one that doesn't need a ground plane for use in your apartment. Once you get in your house, whatever you can both afford and get away with. With radio, height is king so you need your antenna as high as possible as it directly affects the range you will have.

 

Thanks. What power supply do other users have? I read in another thread that a user suggested a Alinco power supply.

 

So search for J-pole antenna for GMRS. I will install a roof antenna once I get a house. 

[berkinet]

Power supply. The key thing to avoid is crap. But, you also do not need some lab quality power supply either. I'd look for something on Amazon that had the capacity @BoxCar noted and generally good reviews. If you want a little meter or digital display, that's fine, but you don't need things like that, especially if you have your own meter available to check the output if there are problems.

 

Antenna.  Are you actually going to have the antenna inside your apartment, like near a window?  If that is the case, I would buy the cheapest 1/4 wave antenna I could find and then mount it on a ground plane. You could then mount it on a baking pan or similar as long as it was at least 13" x 13" or buy something like this.  OTOH  the internet is full of plans to build your own 1/4 wave dipole for close to nothing.  I would not worry about buying an antenna now that you can later move to a house.  Once you get the house, you may well find your needs are different.

 

Also, if you do have the antenna indoors, you should probably keep your transmit power as low as possible. Best would be under 5 watts.

[jec6613]

For a apartment check out the N9tax, he will custom make a GMRS single band antenna for you. At half a meter, it's pretty short, too!

[Danny]

Thanks. Yeah, I don't want to spent a lot of money on an Apt antenna. I rather spend more on a base antenna once we get a house(it's a sellers market). 

 

@jec6613 Thanks I will look at his website.

 

Is TekPower a good brand? I found this one on Amazon and has a really good rating https://www.amazon.com/dp/B00L2M2Y5O/ref=cm_sw_em_r_mt_dp_NYjGFbN93PFB9

[tweiss3]

For an antenna, either get a quarter wave whip (6" approx) and mount it on a ground plane ad identified above, of get an EdFong Jpole antenna (5' long) which requires no ground plane.

 

Both are easy to move around inside and are pretty inexpensive.

[SWSDOG]

I've used both Astron and Motorola power supplies for different radios over the years. Both have worked well for my radio applications.

I'm sure others will chime in here as well, but I feel that it's money well spent if you get a high quality power supply.

[DaveM]

You cant go wrong with an Astron power supply, particularly one with a transformer and pass transistors, not a switcher.  I have several Astron's, 35 and 70 amp supplies that are over 20 years old and have never had a single failure.   Mind you, they can be quite a bit heavier weight wise than a switcher, but can handle anything thrown at them.

[AdmiralCochrane]

Why would one use a 5 ft antenna on a 65cm band radio?

[BoxCar]

Thanks. Yeah, I don't want to spent a lot of money on an Apt antenna. I rather spend more on a base antenna once we get a house(it's a sellers market). 

 

@jec6613 Thanks I will look at his website.

 

Is TekPower a good brand? I found this one on Amazon and has a really good rating https://www.amazon.com/dp/B00L2M2Y5O/ref=cm_sw_em_r_mt_dp_NYjGFbN93PFB9

This supply will meet all your needs. You can buy an inexpensive multimeter at Harbor Freight and have enough left over to get your antenna.

 

https://www.amazon.com/dp/B082TTY3L7/ref=sspa_dk_detail_0?pd_rd_i=B082TN889J&pd_rd_w=aAnjW&pf_rd_p=7d37a48b-2b1a-4373-8c1a-bdcc5da66be9&pd_rd_wg=U3xPt&pf_rd_r=8TN3JZQQQ83GBPR3PBNR&pd_rd_r=c136a1c9-166b-4c81-9433-d7c27f808772&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExODlPQVdDQ1JLTVJLJmVuY3J5cHRlZElkPUEwMTQzNzQ4MTRSRUcxUFNTWUM0QSZlbmNyeXB0ZWRBZElkPUEwMzYzOTU0MkQ3NjJFRDdCWllBQSZ3aWRnZXROYW1lPXNwX2RldGFpbCZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU&th=1

[jec6613]

Why would one use a 5 ft antenna on a 65cm band radio?

Good question ... for repeaters in flat country maybe.  For a portable mount, N9TAX and Ed Fong will both custom cut to a single band 465 MHz antenna that's about 45-50cm long.

[miko1428]

Dpd productions has a good looking gmrs apartment or indoor antenna that I think would fit your needs very well

[berkinet]

Why would one use a 5 ft antenna on a 65cm band radio?

I don't know of any commercial full-wave antennas. Even a theoretical full wave antenna would actually be comprised of two 1/2 wave dipoles, and such an antenna is rather inefficient.  Most antennas are based on a fraction of the wavelength, usually 1/2 wave, or 1/4 wave with a ground plane... which ends up being a 1/2 wave.  Note also, many antenna designs may be longer than a single wavelength. Designs such as the Ed Fong stack elements to modify the radiation pattern and create apparent gain is some direction or plane.

 

Also keep in mind many antennas use a loading coil at the base or mid-point to better match impedance. So, when you are all done, though there is indeed a specific relationship between an antenna's measured length and operating band, it may not be immediately apparent to the casual observer.

[AdmiralCochrane]

These answers don't directly answer my question.   65cm (the wavelength of the GMRS band) is ~25 inches.   A half wave antenna would be ~12 inches.  My home made Slim JIM (which gives me swr's below 1.17) is about 19 inches overall including the lower loop.  Wouldn't a properly tuned J pole for GMRS will be about the same size? 

[berkinet]

... Wouldn't a properly tuned J pole for GMRS will be about the same size? 

 

Apparently not... See: https://www.changpuak.ch/electronics/J-Pole_Antenna-Designer.php

[tweiss3]

These answers don't directly answer my question. 65cm (the wavelength of the GMRS band) is ~25 inches. A half wave antenna would be ~12 inches. My home made Slim JIM (which gives me swr's below 1.17) is about 19 inches overall including the lower loop. Wouldn't a properly tuned J pole for GMRS will be about the same size?

You are correct, a GMRS only would be about 19 inches, but the EdFong is a dual band, and is about 5' long when placed in PVC pipe, including the 12 lead area for clamping. Even at 5' it's very manageable inside and reasonable at $34+ shipping. You can always use fishing line to hang it in a window and it should work well.

[dwmitchell61]

Power supply. The key thing to avoid is crap. But, you also do not need some lab quality power supply either. I'd look for something on Amazon that had the capacity @BoxCar noted and generally good reviews. If you want a little meter or digital display, that's fine, but you don't need things like that, especially if you have your own meter available to check the output if there are problems.

 

Antenna.  Are you actually going to have the antenna inside your apartment, like near a window?  If that is the case, I would buy the cheapest 1/4 wave antenna I could find and then mount it on a ground plane. You could then mount it on a baking pan or similar as long as it was at least 13" x 13" or buy something like this.  OTOH  the internet is full of plans to build your own 1/4 wave dipole for close to nothing.  I would not worry about buying an antenna now that you can later move to a house.  Once you get the house, you may well find your needs are different.

 

Also, if you do have the antenna indoors, you should probably keep your transmit power as low as possible. Best would be under 5 watts.

Midland says stay more than 23" away from the antenna when transmitting on the MXT400, and it is a 40W radio.

[dwmitchell61]

I always prefer a power source capable of at least 150% of the load. Closer you come to the load capacity of the power supply the greater the odds of noise and ripple being induced in the power supply output. The creation of heat within the power supply increases with operation near capacity, also.

[AdmiralCochrane]

Apparently not... See: https://www.changpuak.ch/electronics/J-Pole_Antenna-Designer.php

 

You are correct, a GMRS only would be about 19 inches, but the EdFong is a dual band, and is about 5' long when placed in PVC pipe, including the 12 lead area for clamping. Even at 5' it's very manageable inside and reasonable at $34+ shipping. You can always use fishing line to hang it in a window and it should work well.

 

Yes using the calculator linked, I see the same length ~19"

 

That the antenna mentioned is dual band explains the extra length; I didn't see that in the original mention.  I think Ed makes single band antennas too, so without the dual band mention, I didn't know why a longer one was mentioned. 

[tweiss3]

Yes using the calculator linked, I see the same length ~19"

 

That the antenna mentioned is dual band explains the extra length; I didn't see that in the original mention. I think Ed makes single band antennas too, so without the dual band mention, I didn't know why a longer one was mentioned.

Recommendation was based on cost. His DBJ-UHF is $10 more and is still 4' in length. The dual band could also be reused for other things later. I retired mine from attic operation to field operation for field day or any other quick trip.

[Danny]

I went ahead and purchased the power supply that @boxcar suggested and contacting Ed Fong for a j pole antenna. 

[1URFE57]

Thanks. Yeah, I don't want to spent a lot of money on an Apt antenna. I rather spend more on a base antenna once we get a house(it's a sellers market). 

 

@jec6613 Thanks I will look at his website.

 

Is TekPower a good brand? I found this one on Amazon and has a really good rating https://www.amazon.com/dp/B00L2M2Y5O/ref=cm_sw_em_r_mt_dp_NYjGFbN93PFB9

 

I got two TEKPower Power supply a 30amp that I use for my FTDX3000 and 23 amp which I used for GMRS mobile base so far so good planning to add the TEKPower 50amp in the mix.

[Danny]

I received the j pole from Ed Fong. 

 

I'm trying to look for a good uhf coax cable. I only need like 10-20ft. What is a good cable to buy?

[Lscott]

These answers don't directly answer my question.   65cm (the wavelength of the GMRS band) is ~25 inches.   A half wave antenna would be ~12 inches.  My home made Slim JIM (which gives me swr's below 1.17) is about 19 inches overall including the lower loop.  Wouldn't a properly tuned J pole for GMRS will be about the same size? 

No. The J-Pole antenna is a 1/2 wave length long for the radiating section. The end of the antenna has a rather high impedance making for a very poor match to 50 ohm coax. Thus the extra length is due to an additional 1/4 wave matching section, the section with the short length of extra conductor parallel to the long one, where the tap point selected yields the desired 50 ohms. The overall length will be closer to 3/4 wave length long. At 462MHz the wave length is about 64.7 cm (25.8 inches) and 3/4's of that would be 19.1 inches, just what you measured.

 

http://www.ka3pmw.com/files/jpole_presentation_rev2.pdf