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Superheterodyne vs wattage


WRPH745

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MichaelLax and WyoJoe you have convinced me to take another look at the DB-20G. I do appreciate it's transmit "flexibility".

The very low price point actually turned me off.  The voice in the back of my head said can $100 radio last. That is why I was leaning towards the KG-XS20G.  But are the two of you happy with the DB-20G?

 

Side note:  MichaelLax in another post you mentioned a cup holder mount you are using for for DB-20G. Do you remember which one you purchased?  I have Corolla with very little room for a radio and a cup holder mount would work great in my car?

Thanks.

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7 hours ago, WyoJoe said:

As for mobile radios, I will also recommend the Anytone AT-779UV, just as MichaelLAX recommended. It's a decent 20W mobile GMRS radio, but can be opened up for use on 2M and 70cm ham bands, too. .

For about $100, you get a very compact (5"w x 1.5"h x 4"d), 500 channel radio [snip]

+ 2 on the Anytone AT-779UV.  It solved a few problems for me that a more expensive base radio was having (details of which better discussed in a technical thread).  I even bought a 2nd one for my vehicle. 

One thing though:  WyoJoe:  I am using the Windows based software and I only see slots for 128 channels and can't seem to go any higher.  How are you able to see 500 channels?  It would be helpful for me, because I like to match transceiver channel numbers with my scanner & other radios.

Thanks.

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1 hour ago, WRPH745 said:

MichaelLax and WyoJoe you have convinced me to take another look at the DB-20G. I do appreciate it's transmit "flexibility".

The very low price point actually turned me off.  The voice in the back of my head said can $100 radio last. That is why I was leaning towards the KG-XS20G.  But are the two of you happy with the DB-20G?

 

I have had more positive signal reports on the Radioddity DB than on any other radio I have (Yaesu, Kenwood, etc.).  How long it will last is yet to be discovered.

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"Ed Fong antenna and a better radio."

Ed Fong and better radio should not be in the same sentence. Antenna is everything especially in GMRS. The Ed Fong antenna is like buying the bottom of the barrel Baofeng. If you want a good radio get a real antenna. You dont need to spend $500 on a good antenna, but spending $50 on a home brewed antenna isn't the best. Manage expectations. 

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1 hour ago, Citizen said:

One thing though:  WyoJoe:  I am using the Windows based software and I only see slots for 128 channels and can't seem to go any higher.  How are you able to see 500 channels?  It would be helpful for me, because I like to match transceiver channel numbers with my scanner & other radios.

I was only going by memory of the specs I've seen in the Amazon online listing for the Anytone AT-779UV version of the radio. I did check my software (version 2.01), and it has 500 memory slots, plus PL1, PH1, PL2, PH2, VFO1, and VFO2 slots as well. I'm not sure what all of those last six slots are for, but they are listed after channel 500. I have the NOAA weather channels programmed into slots 494 to 500, and the ones I can receive are working for me.

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28 minutes ago, AdmiralCochrane said:

I agree, Fong wins on marketing, not design, but is there a better pre-assembed antenna at the price? 

I think so, the Harvest brand folded dipole goes for 70 bucks on eBay. The 2 bay dipole goes for 140 bucks on eBay. I think folded dipoles are great b/c they have super wide bandwidth and they are very resilient to noise.

single dipole link: https://www.ebay.com/itm/133810193897?epid=1941709490&hash=item1f27b585e9:g:Y5EAAOSwLCdgUyaI

2-bay link: https://www.ebay.com/itm/133927735178?epid=1941709490&hash=item1f2eb70f8a:g:yowAAOSwIytgUyhQ

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8 hours ago, Citizen said:

One thing though:  WyoJoe:  I am using the Windows based software and I only see slots for 128 channels and can't seem to go any higher.  How are you able to see 500 channels?

6 hours ago, WyoJoe said:

I was only going by memory of the specs I've seen in the Amazon online listing for the Anytone AT-779UV version of the radio. I did check my software (version 2.01), and it has 500 memory slots, plus PL1, PH1, PL2, PH2, VFO1, and VFO2 slots as well. I'm not sure what all of those last six slots are for, but they are listed after channel 500. I have the NOAA weather channels programmed into slots 494 to 500, and the ones I can receive are working for me.

Thanks for that info.

Correction to my earlier postMy mistake, I DO see the 500 channel slots when I pull up the software.  I too was going by memory and must have been thinking of another radio that has only 128.  

T.

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Most of the cost of a radio goes into receiver design. All manufacturers must meet minimum FCC specs for the transmitter, so that cost is fixed. Cheap radios will have simple receivers. SOC, System on a chip receivers have a minimalistic design controlled by software commands. The main thing lacking in these designs is RF preselection . The other problem appears to be the lack of an effective FM limiter circuit. While these radios might seem very sensitive in a controlled environment, they really suck in the real world.

Commercial grade radios and public safety grade radios are tested to EIA 603D. If a radio is decent, it will have published EIA 603D performance specifications. Only a minority of the radios available for GMRS have such published specs.

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39 minutes ago, JLeikhim said:

Most of the cost of a radio goes into receiver design. All manufacturers must meet minimum FCC specs for the transmitter, so that cost is fixed. Cheap radios will have simple receivers. SOC, System on a chip receivers have a minimalistic design controlled by soWhile these radios might seem very sensitive in a controlled environment, they really suck in the real world.

I guess you'll need to provide us with the technical definition of "suck" - because i've used/use dozens of these cheap/SOC radios and they all work just great for my needs - and millions of other people seem to agree.

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I guess you'll need to provide us with the technical definition of "suck" - because i've used/use dozens of these cheap/SOC radios and they all work just great for my needs - and millions of other people seem to agree.
Cheap receivers that lose all sensitivity in urban environments. Radio works fine out in the sticks, but if you get near a bunch of tranmitter towers or downtown with many transmitters, they lose sensitivity. Hearing police transmissions at VHF in the FRS GMRS band, NOAA weather blasting Intermod.

That is the real world, versus hooking a signal generator up to the radio on a bench and reporting it has a terrific -122 dBm SINAD sensitivity. Real world is many signals some hotter than -40 dBM entering the receiver chip.

Also sucky are cheap radios that have very scratchy clicky picket fence noise while in motion. They lack an effective FM limiter that would normally supress the AM components of a multipath condition.

Read the complaints.

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Thats not the real-world that I live in, so i'm glad to see that for everyone like me not in an RF-heavy urban environment, the radios dont "suck" .. Because at first, based on your statement, us non-techy people might have misunderstood you to be saying "they suck", which it seems is not the always case, so thanks for clarifying.

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True, they would work far much less sucky on the moon or way out in the boondocks.

In fact, Midland backs up their 32 mile claim for their GMRS radios by testing them line of sight from a huge hill way out in some wide open rural area. The lawyers are happy, but folks who now have those radios, question the claim when they barely get a half mile in a suburban area.

I have some ICOM IC4008A FRS radios that are superhet, but very basic design with little preselector filtering, just a simple coil. Better than an SOC design. They work very well out in the National Parks. But around town, not so much. I keep them because they are easy to use and the AA batteries last days when camping. My wife and son carry them because they are small.

A radio is a tool like anything else. A battery operated drill from China sold at Harbor Freight might get by for the casual home user. But I have a Japanese Makita drill I purchased in 1980 for $300 in 1980 dollars , that has outlasted all of the cheap drills I bought in the meantime. For $35 You are not getting much of a drill. Same for cheap radios.



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17 hours ago, WyoJoe said:

I was only going by memory of the specs I've seen in the Amazon online listing for the Anytone AT-779UV version of the radio. I did check my software (version 2.01), and it has 500 memory slots, plus PL1, PH1, PL2, PH2, VFO1, and VFO2 slots as well. I'm not sure what all of those last six slots are for, but they are listed after channel 500. I have the NOAA weather channels programmed into slots 494 to 500, and the ones I can receive are working for me.

from poking at it, i suspect those "vfo" slots are related to the last setting of the VFO, but the instructions are...a bit lacking. picked mine up today, and working on programming this evening. first impression is wow, it's small, only a little wider and a little thicker than the mxt115.  definitely seeing the 500 memory slots, both programming manually (which was a bit hit and miss) and in software. second note, @MichaelLAX wasn't lying about the sensitivity...had it powered up on the desk with no antenna, and it was picking up stuff from a 70cm ham repeater around 30 miles out.  currently have it programmed almost entirely for UHF, with the exception of some receive-only VHF stuff, as that's the antenna i have handy that covers what i want to.

on a side note, i grabbed the software from Anytone's website, and ran it through virustotal...got 5 hits for various things.  remembering the 'twin' factor, i went and grabbed the db20-g software from radioddity, and scanned that...no hits. installed, and it even reports the model number in the 'about' menu as at-779uv.  read and programmed the anytone just fine.

i'm keeping my expectations in line with price. mainly i wanted something cheap to throw in the beater car with antennas i already have, that i can also pair it with one of the mag mounts to use in a rental car when travelling. already ordered another antenna, though, as the signal stalk on the truck is just a hair too high for the parking garage at work...found a dual band comet that's a few inches shorter, which should be just enough.

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Like I said previously , the DB20G/ AT-779UV is in the running.  The price point at Amazon is the same once you factor in the coupon.

Assuming, I will unlock either model. If I am reading the thread correctly either model can be unlocked? Any advantage to one model over the other besides what channels are preprogramed in?

Thanks

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6 hours ago, JLeikhim said:

True, they would work far much less sucky on the moon or way out in the boondocks.

In fact, Midland backs up their 32 mile claim for their GMRS radios by testing them line of sight from a huge hill way out in some wide open rural area. The lawyers are happy, but folks who now have those radios, question the claim when they barely get a half mile in a suburban area.

I have some ICOM IC4008A FRS radios that are superhet, but very basic design with little preselector filtering, just a simple coil. Better than an SOC design. They work very well out in the National Parks. But around town, not so much. I keep them because they are easy to use and the AA batteries last days when camping. My wife and son carry them because they are small.

A radio is a tool like anything else. A battery operated drill from China sold at Harbor Freight might get by for the casual home user. But I have a Japanese Makita drill I purchased in 1980 for $300 in 1980 dollars , that has outlasted all of the cheap drills I bought in the meantime. For $35 You are not getting much of a drill. Same for cheap radios.



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Hi there,

You made a lot of good points, thank you.

G.

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I recently got a used Kenwood TS-50S HF all-mode radio, but due to weather I haven't been able to do anything with it: its still in the box... but this past week there was a short window where the snow on the roof melted and no new snowstorms were coming..., so figured we go out Jerry rig some antenna and try to test it.... Now, at the present moment I only have a couple of CB talkies from the 90s and a couple of CCR SDR dongles and a TH-F6a to really compare it to... so testing the receivers side by side on the CB channels should be a good test, again, there was no TX. Those CB talkies are representative, more or less, to the performance of what most cheap CB radios will offer today. Both radios are dual conversion superheterodyne receivers.

We took a 5' firestick up and attached it a metal pole on the roof and ran a 25 feet LMR400 wire through the window back inside, which we will connect to the radios/sdrs, etc.

To make things a bit more complicated, there is a PV solar installation on the roof, which has historically made CB pretty much useless during the day if you place an antenna nearby...

So, fired up the Midland 75-820 connected to the Firestick and as just expected, all the radio picks up is the darn chopping noise of the micro-inverters.

Then the same thing happens again with the RadioShack CB talkie.

The SDR waterfall on SDRsharp are just a hot mess of noise across the entire HF band.

TH-F6a doesn't hear the chopping as bad, but I wonder if its the receiver desensing. Again, its a palm sized talkie, I don't expect it to match for a real HF radio.

Lastly, after connecting the TS-50S to the coax, the first thing I notice is that CB channel 1 is almost quiet, there is barely any chopping noises, a lot less than the TH-F6a; so, the first reaction was to thinking that cable was broken, or that the radio might've desensed but then, a conversation came out loud and clear from the speaker... at that moment I was absolutely blown away. Then quickly tuned the TS-50S to 10.000 Mhz and heard the world clock, yep, right there, came in perfect, no chopper noise either.

Switched back to the TH-F6a but it could barely hear the world clock over the PV noise (so that means its desensed, most likely)....

And the SDR dongles none could hear anything on the 10.000 Mhz.

Obviously the CB radios can't tune down to 10.000 mhz, but it was a good test.

So there you have it: The TS-50S worked extremely well in a very noisy environment, and none of the other radios/SDRs could pick up anything, so if I would've been a total beginner I would've thought the channels were dead and nobody was talking. Turns out, high quality equipment is expensive for a reason.. who knew.

G.

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10 hours ago, JLeikhim said:

Cheap receivers that lose all sensitivity in urban environments. Radio works fine out in the sticks, but if you get near a bunch of tranmitter towers or downtown with many transmitters, they lose sensitivity. Hearing police transmissions at VHF in the FRS GMRS band, NOAA weather blasting Intermod.
 

I picked up a TH-8600 mobile a few years back new for about $100 on sale. I was looking for something super cheap to use in my Jeep. This is the exact problem the radio has. The receiver sucks, I pick up a city fire dispatch station which is about 10 to 15 miles away on several UHF channels I have programmed for GMRS/FRS! The only good thing about it is the case is built like a tank, but that's not what I got it for. You get what you pay for, and maybe not even that in some cases with these CCR's.

https://www.tyt888.com/?mod=product_show&id=39

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On 2/13/2022 at 3:55 AM, WRPH745 said:

MichaelLax and WyoJoe you have convinced me to take another look at the DB-20G. I do appreciate it's transmit "flexibility".

The very low price point actually turned me off.  The voice in the back of my head said can $100 radio last. That is why I was leaning towards the KG-XS20G.  But are the two of you happy with the DB-20G?

Side note:  MichaelLax in another post you mentioned a cup holder mount you are using for for DB-20G. Do you remember which one you purchased?  I have Corolla with very little room for a radio and a cup holder mount would work great in my car?

Thanks.

Very happy: only disappointments are my hope for better CPS software (with cut and paste from other sources, but I work around this issue by programming with empty cells between such things as GMRS and then Repeaters and then Ham etc and plugging in new repeaters as I find them) and no ability to scan for tones, which I solved with a $30 HT.  A 50 watt model would be nice, too! ?

Check this Cup Holder from Amazon.

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3 hours ago, WRPH745 said:

Like I said previously , the DB20G/ AT-779UV is in the running.  The price point at Amazon is the same once you factor in the coupon.

Assuming, I will unlock either model. If I am reading the thread correctly either model can be unlocked? Any advantage to one model over the other besides what channels are preprogramed in?

Thanks

I find no functional differences between the Anytone AT-779UV and the Radioddity DB-20G, and I have yet to discover what benefits come from updating the firmware, which on mine are 2.28 and 2.29.  I use the Radioddity CPS programming software also on my 779s

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43 minutes ago, WRPH745 said:

Thanks everyone for their advice.  I went with the DB-20G.  Since it has band "flexability", I thought it was a good radio to start with till I know where I want to focus my resources.

 

In spite of the occasional programming issues, I really like my AT-779UV / DB-20G radios. From a price/performance perspective, I think this is where you can get the best bang for the buck in a new radio. There may be used commercial radios available at around the same price that offer better performance, but they won't be new at that price, and they have to be programmed, requiring software and a programming cable. Depending on the radio, that can quickly add a lot to the price.

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