My new to me Ameritron 811h

[Sonwatcher]

Does the Ameritron 811h work okay on the 11 m band ?

Don't know. I don't use it on 11m.

 

[Sonwatcher]

I do have a question about the "dip" while tuning. Do you let it rest just after it dips ? The reason I ask is because the "dip" and my highest reading on the watt meter don't happen at the exact moment. Just a very light difference.

 

[airplane1]

Ron, I let mine rest just at the dip on my grid.

26AC148, yes they will work on 11 meters once converted for 10 meter but I dont use mine there.

AP

 

[Captain Kilowatt]

That's true but there are limitations. Old rigs like the Johnson Ranger will tune into just about anything but you can actually load up on the second harmonic if you aren't careful.

Modern linears are usually not designed to work into a VSWR over 2:1.

Solution?

No bux?

Build a tuner from junk parts. They are a great project.

I'll agree with part of that. Modern amps that run finicky ceramic tubes may have a problem with high power and high SWR but at 800 watts max and four fairly rugged 572B tubes that are being run below their normal ratings along with the beefed up tank circuit and power supply he should have no problems at all with a fairly high SWR that would drive a solidstate rig off the air. I don't mean loading into 2 or 3 ohms or into 1000 ohms but something in the 10-500 ohms range depending on reactance.

 

[Sonwatcher]

Build a tuner from junk parts. They are a great project.

I would love to make a simple one. I was told if I had a 28mh roller inductor and a 500mmf variable capacitor and a 250 PICO capacitor I could make a T network . My problem is knowing how to put it all together. If I had the mentioned parts could someone give me an idea of assembly ? And anything else I may need ? I have no electronics background so some things are just plain Greek.

 

[Captain Kilowatt]

I have no electronics background so some things are just plain Greek.

See? You have the knowledge you need to make a Pi network tuner. :laugh:

 

[Sonwatcher]

See? You have the knowledge you need to make a Pi network tuner. :laugh:

 

[HiDef]

I would love to make a simple one. I was told if I had a 28mh roller inductor and a 500mmf variable capacitor and a 250 PICO capacitor I could make a T network . My problem is knowing how to put it all together. If I had the mentioned parts could someone give me an idea of assembly ? And anything else I may need ? I have no electronics background so some things are just plain Greek.

Yup. Build a highpass T network. 2 variable caps are needed. SO-239 into one side of one variable cap. Output of cap to the inductor. The other end of the inductor goes to chassis ground. Juncture of first inductor and input cap to one side of output cap. Other side of output cap to output SO-239.

This is exactly what most common tuners use with the addition of a 4:1 balun hooked to the output SO-239 for balanced use. The 4:1 works better for SWR but a 1:1 may be better for actual power transfer depending on the antenna/feedline length.

This network will load up for low SWR several ways. Always use the most capacitance on the in and out caps for best power transfer.

That's all there is to a Dentron Super Tuner or any of the others.

 

[Sonwatcher]

Do you know of any pics on the web of the above assembly. Not a schem but an actual pic ? I am interested in putting one together if I find the components.

 

[HiDef]

If you google "T network tuner" a whole bunch of stuff shows up.

Here's something worth looking at
Impedance Transforming T-Networks - Antenna Tuner Application

If you look on rigpix and ebay at 90 percent of the hammyhambone tuners made in the 70s or 80s it will be this configuration. Some sellers have good photos of under the hood.

Check out the Dentron and Heathkit tuners.

 

[Moleculo]

Do you know of any pics on the web of the above assembly. Not a schem but an actual pic ? I am interested in putting one together if I find the components.

The pics and review I did of the Ameritron ATR-30 will help some...it's a T network tuner. The pics don't show you exactly how to build it, but it will give you an idea. Ignore all of the circuitry for the meters, balun, and antenna switch; you can add that stuff later if you want. Building one of these tuners really is simple if you can find the parts. I haven't built one, but I have considered do so just for fun. If you already have an external SWR meter, just use that instead of building one into the tuner.

http://www.worldwidedx.com/tuners-m...kw-legal-limit-antenna-tuner-review-pics.html

 

[Sonwatcher]

Thanks guys. I'll try to do some more research.

 

[Sonwatcher]

Has anyone had experience connecting one of these amps to an older transceiver ? I have an FT-101B. I also have an FRB-757 relay that is supposed to work with about any transceiver. The voltages needed to key a relay are found in a wire that come out from the ACC plug. I have an RCA connection I can use for PTT. But my guess is I need to find which wire on the ACC plug contains the voltage for the relay to trip. Any guidance beyond what I have surmised or correction would be greatly appreciated.

 

[BJ radionut]

FT 101B/Amp Relay

Maybe this will help....also see the schematic in the manual the ACC plug is mapped out and shows the NO/NC dry contacts for the trigger switch...for the 811H should work by connecting to the NO/+grd then when PTT is closed the relay will short the line completing the connection and key the amp....
I did the same for my FT950 off of the tuner Acc jack...2 wires off of the NO and put a RCA jack to the amp...then when I use the foot switch(stomp to talk) or VOX it keys the amp also...looks like pins 8 and 9 for your rig
Good Luck
All the Best
BJ

PS: I do not think you need the interface...the amp just requires shorting the 12vdc at the relay jack to ground to key the amp...you can check this by using and RCA plug with 2 wires off of it, then short them together and the amp should key.

 

[Sonwatcher]

Thanks !