SDS100/SDS200: SDS antenna connector is warm

[Fred1]

The antenna connector feel warm. Is this a normal thing to feel heat through the antenna connector? I have a 436 too, it does not seem to do this?

 

[trentbob]

Yes Fred, if you are talking about an SDS 100 it is normal for the radio to be very warm in the area of where the antenna connects. Nothing unusual about this.

 

[Fred1]

Yes Fred, if you are talking about an SDS 100 it is normal for the radio to be very warm in the area of where the antenna connects. Nothing unusual about this.

Thanks brother, 73’s N3LCM

 

[Fred1]

Thanks again maybe talk to you on 442.5 W3SBE in Roxborough

 

[trentbob]

Thanks again maybe talk to you on 442.5 W3SBE in Roxborough

Ah yes, I'm familiar, I'm in the Warminster amateur radio club and usually hang out on 147 .09 K3DN, the input on Grundy Tower is rather close and I reach it with 5w with no problem. Been so busy lately with the holidays I just haven't been that active lately. 73s and have a good New Year!... Bob.

 

[Fred1]

Ok, 73’s have a good new year!

 

[trentbob]

Yep, thanks and I just saw your PM and replied now

 

[n1chu]

The two software defined radios (SDR) from Uniden, namely the SDS100 & SDS200 run warmer than previous non-SDR models. I believe the processor needed for an SDR radio is why. In any event, the SDS100 also needed a larger battery to give the portable a longer run time because of the higher power consumption. I wouldn’t be surprised if the radio, by design, uses whatever means available to loose some of the heat, which would explain why the antenna connection gets warm. Heat is any electronic’s enemy, and engineers go to great lengths to limit as much of it as possible. But as is with anything involving electronics, compromises are made and acceptable standards are met, as is the case with the SDS100.

I believe the heat issue was a concern with the SDS100, due to the case they chose to use (which looks a whole lot like Uniden’s marine portable transceiver). It’s a nice case but it’s also moisture resistant… a feature needed in a marine environment for sure but it doesn’t do much for dissipating heat. (I suspect marine gear is assumed to be used for short transmissions, not a lot of long winded conversations and rag chewing so dissipating heat wasn’t as much of a concern.) But Uniden also touted the moisture resistant feature when marketing the SDS100. (It may not meet military specs or commercial grade but it satisfies consumer grade which is acceptable and was all that was expected.)

An example of concern; Scanner Master sells an aftermarket hard leather case for the SDS100, but not before they took heat dissipation into consideration. Their hard leather case has 5 vent holes on the bottom part of each side panel and is pretty much open on the backside top. (Leaving the belt attachment nub on the radio allows for a spacer which keeps the case from touching the upper backside of the radio, allowing for circulation.

So, heat dissipation was/is a concern with the SDS100. Ideally, holding the radio in the palm of your hand is something I believe came from handheld transceivers, amateur and commercial, a throwback to how heat was managed when transmitting. We all know a transceiver gets warm when transmitting but the transceiver is (usually) held in your hand… we needed to hold it up to our mouths when transmitting, and the palm of our hand acted as a heat sync, pulling heat out of the radio… not so much with the SDS100, as it’s a receive only radio, but the need for a heat sync remains.

I own an SDS100. It has some shortcomings yes, but it also is a heck of a lot of radio. My belief that Uniden was in a rush to get the radio to market in a manner that was cost effective, keeping costs down for both them and us led them to choose an “off-the-shelf” marine case… apparent by both the heat and battery issues. But Uniden’s approach to addressing the issues is admirable. Please do not regard this post as “dissing” Uniden. It’s not not my intention.

These points are not so much speculation on my part but factually vetted boilerplate. That being said, I won’t argue opposing points of view, as it’s still only “One Man’s Opinion”!

 

[Fred1]

Thanks, makes sense on the case choice and characteristics of heat dissipation.
73’s

 

[JoeBearcat]

The SDR-based scanners have to do all functions previous scanners did AND convert the RF spectrum into usable frequency data. This is very processor intensive and results in much more heat.

 

[OpSec]

Yep, it gets warm. If you really want to question something, feel an APX8500 mobile after it's been turned on a while...almost hot enough to make eggs on!