Mobile To Base Converter Kit

[KE0GXN]

Been thinking about trying this in lieu of going with a roof/outside base antenna. I don't feel comfortable/knowledgeable enough on trying to install an outside antenna at this point in the game......yet.

So....after exhausting the search function on here, I came up with the following gear/set-up:

-Laird ABSSCANC 150/450/800 Mobile Antenna

http://www.theantennafarm.com/catalog/laird-technologies-abscanc-1048.html

-Laird MBC800 Base Kit

http://www.theantennafarm.com/catalog/laird-technologies-mbc800-1650.html

-25 Feet of Times Microwave LMR400UF Low Loss Flexible Cable

http://www.theantennafarm.com/catalog/times-microwave-lmr-400uf-1472.html

-Times Microwave TC-400NM Male Connector (To go into the base kit)

http://www.theantennafarm.com/catalog/times-microwave-tc-400-nm-3399.html

-Times Microwave TC-400SM-X SMA Male Connector (To go into my HP-2)

http://www.theantennafarm.com/catalog/times-microwave-tc-400-sm-x-3448.html

I figured this would be the equivalent of an attic, discone install, as far as reception goes. I live in a single story home, so I would not think the attic wouldn't be much higher to influence reception than this set-up. I would also be avoiding drilling holes, running cables into different rooms, etc.

I plan on using a cheap floor lamp or something along those lines as my mounting point, which in turn would make the set-up portable throughout he house.

Looking for any thoughts, opinions on my set-up plan/parts and or experiences anybody may have (pro & cons) with using a mobile converter kit?

Or at the end of the day, should I just save my money and stay with my pizza pan Pro Comm mobile mag mount set-up.....?

 

[W8RMH]

I use the exact setup with a 760-870 MHz antenna and a shorter run of coax and it works great for me. If you have the Extreme Upgrade you can use the RF Power Plot to locate your antenna.

 

[KE0GXN]

The reason I went with 25 feet of coax is for location ploting purposes in different rooms. If the sweet spot is not near where I am sitting, I wanted the freedom to place it and not alter where I placed myself or the unit. I was wondering if it was overkill myself? But from what I have read on here anything less feet wise would make the coax gain minimal, so I went with what I thought would be a little over my need, but too much over that it would start affecting reciption loss....

Does everything else look okay, is the LMR 400 a good coax choice for this application and do all the parts match up for what I need? Anything else you think I need?

And yes, the Extreme Upgrade will be part of the list, if not for nothing more than the RF plot feature.

Anyone else please feel free to chime in, nobody on here has steered me wrong yet! Thanks guys.

 

[KE0GXN]

Utilizing mixing/different brands with this kit?

Another thing I have been tossing around in my head is getting the Larsen 150/450/800 antenna instead of the Laird 150/450/800....would that cause any issues? Personally I like utilizing components of the same brand whenever possible, just feels right for than anything.

Thoughts?

 

[cmdrwill]

Remember the radials need to be sized for the lowest frequency. In your case that would be 18" or so.

 

[KE0GXN]

Will do! Thanks.

 

[mmckenna]

Some ideas to consider.

LMR-400 is good cable, but it's also a bit stiff. Connecting it directly to your scanner can put a lot of strain on the antenna connector. Usually this strain will cause a failure, and often it's the jack on the radio. Not impossible to repair, but not easy.

I'd really strongly encourage you to not attempt to connect the LMR-400 directly to the radio.

Instead, use a short jumper made out of RG-58 or similar cable. Put an SMA on one end and a female N on the other. This flexible jumper will reduce the chances of damaging your radio.
You could do the same thing at the antenna, but if you mount/strain relief things well, you won't have an issue.

Also, the parts you spec'd out include crimp on LMR400 connectors. Do you have the correct crimping tool for those?

LMR-400 also might be overkill for a 25 foot run. The difference in losses at 25 feet, even at 800MHz where the losses are greatest, is minimal.
LMR-400 = .941dB loss
LMR-240 = 1.837dB loss
Double the loss, but likely you won't notice it. It'll also be easier to work with and will be more flexible, negating the need for the jumper I mentioned above.

 

[KE0GXN]

Some ideas to consider.

LMR-400 is good cable, but it's also a bit stiff. Connecting it directly to your scanner can put a lot of strain on the antenna connector. Usually this strain will cause a failure, and often it's the jack on the radio. Not impossible to repair, but not easy.

I'd really strongly encourage you to not attempt to connect the LMR-400 directly to the radio.

Instead, use a short jumper made out of RG-58 or similar cable. Put an SMA on one end and a female N on the other. This flexible jumper will reduce the chances of damaging your radio.
You could do the same thing at the antenna, but if you mount/strain relief things well, you won't have an issue.

Also, the parts you spec'd out include crimp on LMR400 connectors. Do you have the correct crimping tool for those?

LMR-400 also might be overkill for a 25 foot run. The difference in losses at 25 feet, even at 800MHz where the losses are greatest, is minimal.
LMR-400 = .941dB loss
LMR-240 = 1.837dB loss
Double the loss, but likely you won't notice it. It'll also be easier to work with and will be more flexible, negating the need for the jumper I mentioned above.

Thanks for the feedback!

I choose the LMR 400UF I linked to via Antenna Farm, specifically based off the producer's website (Times Microwave) specs, stating that it would be ideal for short antenna runs requiring very flexible coax. I do not have any experience with coax, so I figured the fact it was advertised as "flexible" and the info they put out on it on their site, that it would be ideal for my set-up. May have to rethink that....

As far as crimping, etc...For a $8.00 fee, Antenna Farm will custom make a coax run for you. I was going to pay that and let them deal with all the crimping and so forth. The coax would be shipped custom made and ready go with whatever coax brand/type, connectors or length I chose.

I am still on the fence about my coax length....? What coax length would you recommend for this application? I plan on mounting the converter kit on a cheap coat rack or floor lamp, thus making the set-up portable throughout my house. I also want enough coax that will give me the freedom to sit or relax anywhere I want, regardless of where my reception "sweet spot" may be in a particular room.

If you could elaborate more on the coax issue, I would greatly appreciate it.....kind of just put this set-up plan together by running searches on this forum, google, etc... I don't have any knowledgeable acquaintances on this subject, so any input you could provide I can surely use.

Here is the link I referred to about Times Microwave LMR 400 Ultraflex Communications Coax:

www.timesmicrowave.com/documents/resources/LMR-400-UF.pdf

 

[cmdrwill]

I am still on the fence about my coax length....? What coax length would you recommend for this application? I plan on mounting the converter kit on a cheap coat rack or floor lamp, thus making the set-up portable throughout my house. I also want enough coax that will give me the freedom to sit or relax anywhere I want, regardless of where my reception "sweet spot" may be in a particular room.

In the above case RG8X mite be a good choice for short runs and it is flexible.

 

[KE0GXN]

In the above case RG8X mite be a good choice for short runs and it is flexible.

I will do some research on RG8X coax. Thanks!

 

[n5ims]

I will do some research on RG8X coax. Thanks!

RG-8X is good coax for HF use, but quite lossy above 50 MHz or so. For receive only short runs, you can go with some RG-6 (quad shield, would be preferred) which is the same size as 8X and easy to find, very low cost, and will work better. As I indicated, for a receive-only application like a scanner you can ignore those folks that will holler that it's 75 ohm and your scanner should use 50 ohm coax (true for transmit or single frequency application, but for wide band scanner it will work just fine).

Just so you know, RG-6 is designed for TV (the quad-shield stuff for both TV and satellite) use and guess what, those frequencies are the same or even higher than your scanner works on. You may need some adapters (oh, the extra loss!) to match what's already on the coax to your antenna and scanner. While it is true, those adapters will give you some loss, if you get quality ones, they'll be less than you'll often find on the cheap, automated crimp connectors put on most pre-made cables (and those may not match what you need anyway). Now, if you custom order your cable, you can generally get the connectors that you actually need that are installed correctly.

 

[KE0GXN]

RG-8X is good coax for HF use, but quite lossy above 50 MHz or so. For receive only short runs, you can go with some RG-6 (quad shield, would be preferred) which is the same size as 8X and easy to find, very low cost, and will work better. As I indicated, for a receive-only application like a scanner you can ignore those folks that will holler that it's 75 ohm and your scanner should use 50 ohm coax (true for transmit or single frequency application, but for wide band scanner it will work just fine).

Just so you know, RG-6 is designed for TV (the quad-shield stuff for both TV and satellite) use and guess what, those frequencies are the same or even higher than your scanner works on. You may need some adapters (oh, the extra loss!) to match what's already on the coax to your antenna and scanner. While it is true, those adapters will give you some loss, if you get quality ones, they'll be less than you'll often find on the cheap, automated crimp connectors put on most pre-made cables (and those may not match what you need anyway). Now, if you custom order your cable, you can generally get the connectors that you actually need that are installed correctly.

The adaptors will be installed by Antenna Farm, due to the run being custom made by them. So I am guessing I should have no worries there. For my coax run, price is not a huge factor (to a point), I am not rich by any means, however I just soon pay a few extra bucks due to my run being short and from what I have seen, costs would not be astronomical, so I would soon just pay for quality. I am not looking for Helix type stuff, but something with the lowest loss possible that won't bankrupt me. If that makes any sense....

 

[KE0GXN]

Forgot to to ask you guys.....

Antenna Farm offers an optional heat shrink for the connector(s) installation...what is that and what is it for? Is it worth doing?

 

[n5ims]

Forgot to to ask you guys.....

Antenna Farm offers an optional heat shrink for the connector(s) installation...what is that and what is it for? Is it worth doing?

Heat shrink tubing. There to help waterproof the connection. It can be standard heat shrink tubing that works, but may not seal 100% or a modification that includes some sealant or glue that pushes it up to a near 100% seal. That said, it's still a good idea to further seal it with coax-seal and/or a good grade of electrical tape to not only seal the connection from water, but prevent it from being damaged by the UV light from the sun.

 

[mmckenna]

Thanks for the feedback!

I choose the LMR 400UF I linked to via Antenna Farm, specifically based off the producer's website (Times Microwave) specs, stating that it would be ideal for short antenna runs requiring very flexible coax. I do not have any experience with coax, so I figured the fact it was advertised as "flexible" and the info they put out on it on their site, that it would be ideal for my set-up. May have to rethink that....

It's flexible compared to other similar sized coaxial cables. It's not as flexible as a smaller gauge cables. The issues with connector damage is still an issue due to cable weight and stiffness.

I am still on the fence about my coax length....? What coax length would you recommend for this application? I plan on mounting the converter kit on a cheap coat rack or floor lamp, thus making the set-up portable throughout my house. I also want enough coax that will give me the freedom to sit or relax anywhere I want, regardless of where my reception "sweet spot" may be in a particular room.

Just get the length you need. Don't get too hung up on the loss figures when looking at a few extra feet. Your radio/ears won't be able to tell the difference.

If you could elaborate more on the coax issue, I would greatly appreciate it.....kind of just put this set-up plan together by running searches on this forum, google, etc... I don't have any knowledgeable acquaintances on this subject, so any input you could provide I can surely use.

Coax losses increase with cable length, so just use what you need. Don't get hung up on the 0.x dB loss numbers, you and your radio won't be able to hear the difference.
If you were doing a permanent exterior mount I'd say invest in the best cable you can afford, but for 25 feet and an interior antenna, save your money. What you are planning to do will probably improve reception, but don't expect wonders. You'll still be limited by lack of antenna height, interference from RFI sources inside your home, and signal blockage by metal objects/building materials.
You're on the right track, but don't get too hung up on small incremental 0.xdB numbers.

Forgot to to ask you guys.....

Antenna Farm offers an optional heat shrink for the connector(s) installation...what is that and what is it for? Is it worth doing?

If it's "marine grade" heat shrink with the internal adhesive, then it does help with weather sealing, but probably not something you need. Where it can provide a benefit is with strain relief. Where cables like this will often fail is at the point where it's crimped. Frequent flexing will work the crimp loose over time. The heat shrink can help reduce that.

 

[KE0GXN]

It's flexible compared to other similar sized coaxial cables. It's not as flexible as a smaller gauge cables. The issues with connector damage is still an issue due to cable weight and stiffness.



Just get the length you need. Don't get too hung up on the loss figures when looking at a few extra feet. Your radio/ears won't be able to tell the difference.



Coax losses increase with cable length, so just use what you need. Don't get hung up on the 0.x dB loss numbers, you and your radio won't be able to hear the difference.
If you were doing a permanent exterior mount I'd say invest in the best cable you can afford, but for 25 feet and an interior antenna, save your money. What you are planning to do will probably improve reception, but don't expect wonders. You'll still be limited by lack of antenna height, interference from RFI sources inside your home, and signal blockage by metal objects/building materials.
You're on the right track, but don't get too hung up on small incremental 0.xdB numbers.




If it's "marine grade" heat shrink with the internal adhesive, then it does help with weather sealing, but probably not something you need. Where it can provide a benefit is with strain relief. Where cables like this will often fail is at the point where it's crimped. Frequent flexing will work the crimp loose over time. The heat shrink can help reduce that.

Based on your advice I now decided to go with a 25 foot run of LMR 240UF described in the link below:

http://www.theantennafarm.com/catal...uf-1464:59985f944dcc7ec655e94dcc9cfbfe2f.html

I also will request the heat shrink on the connectors, for nothing else to help with the strain relief you mentioned. Its only a $1 more to the already $8 custom coax/connector install fee.

What do you think?

 

[mmckenna]

Based on your advice I now decided to go with a 25 foot run of LMR 240UF described in the link below:

http://www.theantennafarm.com/catal...uf-1464:59985f944dcc7ec655e94dcc9cfbfe2f.html

I also will request the heat shrink on the connectors, for nothing else to help with the strain relief you mentioned. Its only a $1 more to the already $8 custom coax/connector install fee.

What do you think?

That's what I'd do if I was in your shoes. It'll make life easier than wrestling with the heavier coaxial cable. You could probably go with the non-UF cable and be just fine.

 

[KE0GXN]

That's what I'd do if I was in your shoes. It'll make life easier than wrestling with the heavier coaxial cable. You could probably go with the non-UF cable and be just fine.

Awesome! Just to be clear would this non-UF coax be fine?

http://www.theantennafarm.com/catal...40-1458:a8ce32953d199e1f564a6972d4dd056d.html

 

[prcguy]

I would also recommend LMR240 for the length and frequency range and that's what I use on most of my portable antennas. I also use hot glue heat shrink as a strain relief.
prcguy

Based on your advice I now decided to go with a 25 foot run of LMR 240UF described in the link below:

http://www.theantennafarm.com/catal...uf-1464:59985f944dcc7ec655e94dcc9cfbfe2f.html

I also will request the heat shrink on the connectors, for nothing else to help with the strain relief you mentioned. Its only a $1 more to the already $8 custom coax/connector install fee.

What do you think?

 

[KE0GXN]

I would also recommend LMR240 for the length and frequency range and that's what I use on most of my portable antennas. I also use hot glue heat shrink as a strain relief.
prcguy

Like I stated before, no one on here has steered me wrong yet....thanks!