Base station transmits well but has poor reception

[tjcasper93]

Hello everyone,

I have a perplexing situation.  I've installed a base station where we live.  It transmits extremely well but has poor reception.  For example, my brother will drive in his car away from the house as we converse back and forth.  Within a mile or so he starts to break up, it gets statically, fuzzy, etc.  Then I can't hear him at all.  Meanwhile he can hear me plain as day.  In fact he can be several miles away and he picks up my transmission with great clarity.  As a comparison I can use the radio in my car sitting in the driveway and from the same distances I can hear him quite well. 

 

Using another example my base station pulls in one weather station.  In my car, sitting in the driveway, I pull in multiple weather stations.

 

For equipment my base station, my car, and my brother's car all use Midland MXT500 radios.  The antenna for the base station is a Larson BSA450.  I am using 35 feet of LMR400 from the antenna to the radio.

 

As a side note I've tried using various locations for the antenna on our roof but get the same result.  I've also tried using the radio from my car....same result.  I've used other antennas.....same result.  And I bought new LMR400.....same result.

 

Thanks in advance for any help you can give me!

[gortex2]

You mention your base but what is the car using for an antenna ? 

 

[SteveShannon]

On 9/24/2022 at 11:41 AM, tjcasper93 said:

Hello everyone,

I have a perplexing situation.  I've installed a base station where we live.  It transmits extremely well but has poor reception.  For example, my brother will drive in his car away from the house as we converse back and forth.  Within a mile or so he starts to break up, it gets statically, fuzzy, etc.  Then I can't hear him at all.  Meanwhile he can hear me plain as day.  In fact he can be several miles away and he picks up my transmission with great clarity.  As a comparison I can use the radio in my car sitting in the driveway and from the same distances I can hear him quite well. 

 

Using another example my base station pulls in one weather station.  In my car, sitting in the driveway, I pull in multiple weather stations.

 

For equipment my base station, my car, and my brother's car all use Midland MXT500 radios.  The antenna for the base station is a Larson BSA450.  I am using 35 feet of LMR400 from the antenna to the radio.

 

As a side note I've tried using various locations for the antenna on our roof but get the same result.  I've also tried using the radio from my car....same result.  I've used other antennas.....same result.  And I bought new LMR400.....same result.

 

Thanks in advance for any help you can give me!

Swap the base station radio with one of the radios that works. If the problem follows the radio you know it is something with the radio. If the house continues to have poor reception then it’s not the radio. By logically eliminating things you can rule them out. In the end perhaps it’s just something in the house that’s causing poor reception. 

[tjcasper93]

Hi, regarding the first question I am using a Browning ‎BR-176-S for the car.

Also, thanks for the advice on swapping radios.  I've already tried that and get the same results.

Here's something interesting, however that I just discovered today.  When I unscrew the antenna about half way I get excellent reception, pulling in several weather stations, some over 100 miles away.  When I do that the SWR goes through the roof at around 5.50.  But when I screw down and tighten the antenna again I lose my weather stations but the SWR drops to 1.17.

[tcp2525]

26 minutes ago, tjcasper93 said:

Hi, regarding the first question I am using a Browning ‎BR-176-S for the car.

Also, thanks for the advice on swapping radios.  I've already tried that and get the same results.

Here's something interesting, however that I just discovered today.  When I unscrew the antenna about half way I get excellent reception, pulling in several weather stations, some over 100 miles away.  When I do that the SWR goes through the roof at around 5.50.  But when I screw down and tighten the antenna again I lose my weather stations but the SWR drops to 1.17.

Your antenna isn't tuned for the VHF weather band and comes in better when you open up the ground, that's normal. As for your other problem, I'm not sure. I'd have to be there to go over it and see what's going on. 

[gortex2]

Have you checked the VSWR on the mobile yet ? I'd verify it is good also. What is the VSWR on it ? NMO mount on the roof or some other place ? 

 

[MichaelLAX]

I personally have no experience with Midland radios.

The major "feature" of these radios, as I read about them on this forum, is their simplicity to use out of the box; but not necessarily price.

Have you tried using a different radio in your base and repeat the experiment with your brother?

Perhaps the Midland just has a bad "front end" which hobbles its receiver.

UPDATE: I just read @Shannonsame suggestion!  and your reply, but did you try a different radio other than Midland?

[tjcasper93]

Hello again,

 

SWR on the mobile is really good.  I don't remember exactly but it was in the 1.2 range.  The mount is in the center of the roof and is NMO.

 

I've only tried the Midland MXT500.  That's what my brother and I purchased back when they came out.  I guess I could give another radio a try, though I'm not necessarily wanting to spend a whole lot more.  Any suggestions on a decent alternative to the MXT500?

[OffRoaderX]

3 minutes ago, tjcasper93 said:

Any suggestions on a decent alternative to the MXT500?

KG-1000G.. More capable and less expensive.. However a bit more complicated.

[marcspaz]

Based on what you said on Sunday at 08:42 PM, about the receiver being excellent when the centered of the coax is hooked but, but get bad when you screw the ground collar on, I'm thinking you have a bad coax or bad mount, regardless of how good your SWR is. It indicates a possible partial short.

[SteveShannon]

34 minutes ago, marcspaz said:

Based on what you said on Sunday at 08:42 PM, about the receiver being excellent when the centered of the coax is hooked but, but get bad when you screw the ground collar on, I'm thinking you have a bad coax or bad mount, regardless of how good your SWR is. It indicates a possible partial short.

Exactly. This can be caused (I know you already know, Marc) by too sharp of a bend in the coax or too tight of a cable tie which squeezes the coax too tight, causing the inner conductor to migrate through the insulation (especially foam core) and contact the shield. 

This is the kind of issue I thought he could self diagnose when I suggested changing out every element one at a time to logically troubleshoot the issue: radio, coax, antenna.  Of course it’s possible that a person replaces the coax and makes the same installation mistakes as before, causing the same problem. It’s also possible to take a piece of coax and move it somewhere else and have the condition reverse itself, resulting in the inner conductor no longer touching the shield, at least temporarily, but personally I would discard or at least cut out the bad spot and repurpose a failed coax cable.

[marcspaz]

@Sshannon  Don't laugh too hard, but I messed up a connection on my VHF/UHF cable to the point where, when it was bent a certain way, while connected to the radio, it didn't work well at all.  I think there was a stray ground stand or two floating around. 

 

When I took the cable off the radio and put my meter inline, the cable bent another way, alleviated the partial short and tested out perfectly.  I chased it for 2 days before I just happened to have the radio keyed, looking at the meter and moved the meter out of the way to look at my personal data sheet I had been building, to compare numbers from earlier.  The SWR jumped to 19:1 for a flash.

 

I ended up cutting the end off and installing a new clamp style PL259.  I just my insertion loss in half and the radio started working like a rock star. 

 

BTW, I think the clamp style UHF connectors work pretty well for an affordable alliterative to an N type, for use on the 400-500 MHz range.  Not sure if you have tried them.  The US made connectors are about $100 each, but I found some really good quality Chinese units on Amazon for about $25 each.

 

[SteveShannon]

I promise I won’t laugh, except to commiserate. I’ve chased similar things before, many of them my own doing!  I’ve felt pretty humble when I’ve figured them out also. 

I consider troubleshooting the relentless application of logic.  It’s one of my favorite things to do, but it can seem so illogical sometimes.

i haven’t seen those connectors.  Do you have a link?

[marcspaz]

3 minutes ago, Sshannon said:

i haven’t seen those connectors.  Do you have a link?

Sure do.  They are from XRDS -RF, on Amazon.

 

This is the one that is $25. per pack.    They also make SO-239 and N connectors, but I haven't tried them yet.

https://www.amazon.com/Connectors-5-Pack-PL-259-Connector-LMR400/dp/B08PKG7XB2/ref=sr_1_3?crid=1MJEAXDHXWD02&keywords=clamp+pl-259&qid=1664290461&qu=eyJxc2MiOiIyLjAyIiwicXNhIjoiMC4wMCIsInFzcCI6IjAuMDAifQ%3D%3D&sprefix=clamp+pl-259%2Caps%2C135&sr=8-3

[SteveShannon]

1 hour ago, marcspaz said:

Sure do.  They are from XRDS -RF, on Amazon.

 

This is the one that is $25. per pack.    They also make SO-239 and N connectors, but I haven't tried them yet.

https://www.amazon.com/Connectors-5-Pack-PL-259-Connector-LMR400/dp/B08PKG7XB2/ref=sr_1_3?crid=1MJEAXDHXWD02&keywords=clamp+pl-259&qid=1664290461&qu=eyJxc2MiOiIyLjAyIiwicXNhIjoiMC4wMCIsInFzcCI6IjAuMDAifQ%3D%3D&sprefix=clamp+pl-259%2Caps%2C135&sr=8-3

Those look similar to the very fine connectors from M&P:

https://www.gigaparts.com/connector-for-airborne-5-cable.html?utm_term=sku-zmp-co-uhf-5m-s&gclid=CjwKCAjwvsqZBhAlEiwAqAHElRQb2BuWzLP0UCdEV-6XgcxxI5MnVyIGXMVlD5kMmFClbrEsMXvgDBoCFpgQAvD_BwE

[marcspaz]

10 minutes ago, Sshannon said:

Those look similar to the very fine connectors from M&P:

https://www.gigaparts.com/connector-for-airborne-5-cable.html?utm_term=sku-zmp-co-uhf-5m-s&gclid=CjwKCAjwvsqZBhAlEiwAqAHElRQb2BuWzLP0UCdEV-6XgcxxI5MnVyIGXMVlD5kMmFClbrEsMXvgDBoCFpgQAvD_BwE

 

Yes, Sir. Same style for grounding and insulation.  One of the things I am partial to with the XRDS is that the center lead gets soldered at the bottom of the pin. So there is no splatter in the collar threads and you don't have to worry about being sure there is no excess solder on the lip or outside edge of the tip, causing potential fitment issues. Makes life a lot easier. 

[SteveShannon]

44 minutes ago, marcspaz said:

 

Yes, Sir. Same style for grounding and insulation.  One of the things I am partial to with the XRDS is that the center lead gets soldered at the bottom of the pin. So there is no splatter in the collar threads and you don't have to worry about being sure there is no excess solder on the lip or outside edge of the tip, causing potential fitment issues. Makes life a lot easier. 

I ordered a set of 5. What the hell.

Thanks for the heads up. 
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