What Transmitter gets out the best ???

in my opinion the amt5000 hands down. i've had the 3000, THII, rangemaster and the 5000 beats them all.

Transmitters and antenna types to use are like selecting a pair of leather boots. Finding the right pair so they wear in properly and fit nicely.

There are cheap shoes and there are expensive shoes.

Same with transmitters and antennas.

If you are a do it yourself type, you can build both and save a ton of money and learn a great deal about your own systems and local conditions to make it perform well.

Regardless of which type of AM transmitter you get, they all are going to need a good ground system and properly loaded/matched radiator.

The two pricey models have two advantages to them, they both have internal matching networks for their intended radiator type, and both carry FCC certification.

The rest in your list, next to the TH units, are not FCC certified but are compliant, which really doesn't mean anything when it comes to an inspection. But they are designed to operate within the rules if you build them per the instructions and use the parts included with the kits and not modify them to operate outside of the Part 15 limits.

I cannot vouch for the SSTran series but so far we have seen a few test examples done by members who have both the 3K and 5K units. So far there are some good reports, but not a single report of a 5K unit running on a well built 3 meter antenna system as of yet.

There is a video posted in another thread demonstrating a well built 3 meter antenna system with a AMT3K unit. Naturally we can assume the 5K unit will do just as well and perhaps even better with the 5K's Class E final design and inclusion of internal matching toroid transformer.

The only thing I do not find highly appealing in both the Hamilton and AMT 5000 is that questionable power adjustment control, put there in order to "compensate" for antenna system looses. Well a 3 meter antenna system is highly inefficient to begin with. The FCC rules clearly call for a maximum of 100mW final input power....PERIOD. Now its up to you but with those two transmitters, the Hamilton and AMT5K you can adjust that power pot all you want and take the risk of an inspection and getting tagged for that over power operation, despite the excuse of compensating for antenna looses. The rules do not say we can jack up our power level beyond 100mW to compensate for antenna system looses. So keep that in mind.

I say that because there was a station that got taken off the air, not for excessive power, but for excessive range due to their antenna system having more length than permitted, and they thought it was perfectly fine...until the FCC inspector showed up and said "nope ye ground is much much too long...shut er down"..and they did. Even after choking that ground path with a special built toroid inductor on the ground lead, that did not reduce the ground lead length and they still got the tag..and taken off the air.

So run the risk if you like. As my good friend in Denver at the FCC field offices there once told me.."In the USA you are free to do whatever you want..even on the radio...just make sure your prepared for the responsibility of your actions".

Bottom line..besides the financial bottom line, take a lot into consideration for yourself and not just go by popular influences by excited users who are not going to be around when that inspecting agent does come knock at the door. And don't just readily accept anyone's opinion..including mine.

Go research for yourself and learn all you can before grabbing all these opinion's hands and taking that big leap off the cliff saying "Yes We Can/We Cant Wait".

In other words, don't just "go for it" as said by one individual here at one time that really should not have given what they do and market.

Happy Hunting!

RFB

The two pricey models have two advantages to them, they both have internal matching networks for their intended radiator type, and both carry FCC certification.

The rest in your list, next to the TH units, are not FCC certified but are compliant,

Actually there's a 3rd advantage to the "pricey models"..
It's already built and ready to transmit - Basically they're a turn-key operation transmitters.
Whereas the others are a box of parts that you must assemble involving a lot of soldering and other construction before you can even begin to experiment with transmitting.

As for the TH.. I always thought they were certified ??

I will suggest that the AMT5000 transmitter from sstran.com gets out the best, based on one very logical fact...

The efficiency of the final stage is 98%.

That means that the 100mW maximum power at the input to the final RF stage gets 98% transferred through the final RF stage to the antenna.

So far no other Part 15 transmitter has achieved such good efficiency.

Yeah that efficiency factor would really mean something if we could work with antennas that were not so darn short.

RFB

squeezing every last bit of efficiency out of the transmitter and antenna does make a difference. it's not any one thing that makes any real difference but the total of antenna system and final rf stage efficiency that makes the difference.

if people didn't keep trying to tweak every little bit of efficiency out of these transmitter we would never have sstrans or hamiltons. we would still be tinkering with crappy old school 60's designs that go 200 ft.

Thanks for the posts 🙂

I am leaning towards the Procaster.
It seems to have the best ideas in the over all package.

In response to RFB's comment "The only thing I do not find highly appealing in both the Hamilton and AMT 5000 is that questionable power adjustment control, put there in order to "compensate" for antenna system looses." there are two different situations where the power control is useful.

For operation under 15.209 where the field strength is limited then the power control does indeed "compensate for antenna loss" but this is proper as long as the field strength limit is not exceeded.

Under 15.219 where the DC input to the final amplifier is limited to 100 mW or less the adjustment is not used to compensate for antenna loss, rather it is to adjust the power input up to the limit. A transmitter using a high efficiency final is sensitive to the antenna loading in regard to final input power. For example, if adjusted for 100 mW with an untuned antenna and then the antenna is tuned the power input will increase because more power is being delivered to the load. The power then needs to be adjusted down to compensate. In this case it is not antenna loss which is to be compensated but rather the loading due to antenna match.

I don't see a problem with adjustable power as long as it is used properly.

Neil

I wonder what the efficiency of the final stage of the ProCaster or Rangemaster is? And it would be great if someone was finally able to test the AMT5000 with a 3 meter whip (such as both those other transmitters use - comparing apples to apples).

But let's get a little real here. There are lots of factors that affect the overall range of a Part 15 AM transmitter, and all of them, no matter how efficient, will get their signal trashed from dusk to dawn. Here just across the border from Seattle, at this time of the year, you get a good AM signal for about 8 hours a day. For the remaining 16 hours, my signal drops from over a mile to 1-2 city blocks (that's why I moved over to FM, which at least has a relatively consistent signal 24/7, affected a bit by weather).

Unless you're in this hobby just for the experimentation, I don't think you can go wrong with any of the higher end transmitters. Get the one with the most/preferred features for your budget. I'd spend the time you can argue which one's better in programming your station, building your website, getting the word out (if that's important to you), etc.

[And my personal opinion is: Get an Industry Canada/FCC certified unit. Compliant is nice, but ultimately you're taking the word of the manufacturer, as very few can actually properly test that out in the real world. And yes, you can still have an illegal installation with a certified transmitter, but if you're questioned, you start from the basis of looking like you're at least attempting to be legal). You can get a used Rangemaster for $400-500, not sure about the ProCaster used market, but a new one's not much more than that. For me, the AMT5000 is interesting, but it's close to $300, you have to put it together yourself (not my forte) as well as tune it up, and it's not certified.]

I am leaning towards the Procaster.
It seems to have the best ideas in the over all package.</cite

Not trying to discourage your leaning, But just a heads up: There's a Hamilton Rangemaster currently priced at $350 (and no bids), with 25 hours to go on ebay: http://www.ebay.com/itm/320807416835

(If only I were currently able to bid.).

I am leaning towards the Procaster.
It seems to have the best ideas in the over all package.

Not trying to discourage your leaning, But just a heads up: There's a Hamilton Rangemaster currently priced at $350 (and no bids), with 25 hours to go on ebay: http://www.ebay.com/itm/320807416835

(If only I were currently able to bid.).

Thank you Rich !!!