Q1: If I have understood the PS correctly, after I have gotten the PS working at max 1.5kW RF out, can I assume that linearity of the output from the amp will be equally good at 1kW or say 800W? Yes. RF-KIT's -55 dB coupler will be fine at high power and typical exciter-only power levels, depending...

Even RG400 would be a good option. Easier for me to have one common type of coax in the shack rather than different sizes and all the different connectors associated with it. I use RG400 for all shack RF transmission cabling and RG316 for small-signal applications like PureSignal sampling and GPSDO...

I've long been suspicious of Times' spec of >90 dB shielding effectiveness from their LMR series of cables. That spec is nonsense as it doesn't convey effectiveness as a function of frequency. There's no way Times can justify >90 dB effectiveness across a broad RF spectrum, especially at HF. At HF, ...

For RF sampling and 10 MHz external reference, I use preassembled BNC-to-SMA RG-316 cables. Teflon dielectric, FEP jacket, silver-plated inner conductor and shield. Have a look at eBay item number: 141559843103 . The four-foot cable length is only USD $12 with free shipping from California. Or, this...

Wow, 25 ms through 19 connection hops. Amazing.

Paul, W9AC

I have to say that I have a 600mbps full duplex fiber conexion at home and 300mbps at the remote location. My latencies are arround 25ms, so it runs fine with ringbuffers set in AUTO with no under/overflows. Is that a fiber-to-fiber connection on both ends of the link? I suspect you have few ISP ha...

Sigi, great info. Thanks!

Paul, W9AC

I'll soon be adding a Hermes Lite 2 to my desktop setup together with an existing ANAN 7000DLE. A few questions: 1) Can the same Thetis software be used in the current directly to operate two radios? Or, will a separate download be required into a different directory? 2) It's mentioned above that a ...

Downloads OK here. No warnings using Microsoft Edge.

Paul, W9AC

This morning's test wasn't meant to be a thorough analysis. I wanted to determine if CESSB and CFC can coexist and not create excessive grunge of the kind that's been reported. In fact, most of the distortion heard results when COMP and CFC are engaged with default CFC values, without CESSB active. ...

This morning, I tried the CFC-CESSB settings as suggested in the latest Thetis operating manual. Following this advice, I found that harshness is greatly diminished whether or not CESSB is engaged. So, it's possible that some ops are not taking this advice because at least in my case, it does requir...

I've read Dave's paper I don't know how many times. Toward the end of his paper, he cautions us to not drive the CESSB algorithm into compression. But rather to use multiband baseband processors (CFC passes that bar) and then use CESSB at the very end to only remove the Hilbert artifacts. While I l...

A while back Dave Hershberger and I exchanged messages concerning CESSB as well as some historical material that we shared when we worked at the same AM/FM broadcast stations while I attended Norther Illinois University in DeKalb, Illinois -- the same station as Chief Engineers but during different ...

Paul, I am wondering what the numbers are on Options 1 form in your case? Mine may be off for all I know. I have only changed the PTT and RF delays, nothing else if my memory serves. 73 de Juha NI2M Juha, My CW settings won't apply to you for several reasons as I'm using a specialized Channelmaster...

Can you capture the transmitted CW waveform in the time domain with an oscilloscope? That will tell us a lot about the root cause of any excessive keying bandwidth, hot-switching, etc. It may be easiest to sample at the input to your dummy load with a "T" coaxial adapter.

Paul, W9AC

The Dow-Key 401 is approximately 50% smaller than the 402 series but is only offered with SMA coaxial-type connectors, which I personally prefer when power isn't an issue. I've been using the 401-2208 for low-power RF switching applications. Overall specs of the 401 series are better too. https://ww...

Taking Scott's suggestion a step further, you could automatically control the relay operation with Thetis' OC Control menu. Because you are dedicating each amp to specific bands, this should work well. Just pay attention to the open-collector rating. I like using Dow-Key flat SMA RF relays. They're ...

Thanks for the fotos. With these kind of relays I managed to switch 5 watts on 144MHz. I would not dare to use them for 100 watts. What do you think how long they will survive? cheers Volker It's worth a try and easy enough to replace if it fails. And if it does, I'll send him an Aromat/Matsushita ...

I went back and looked at my pics and I did take a picture of the new relay. It is mounted upside down with some silicone RTV. Wires run from the pads of the old relay to the pins of the new reed relay. Well done. As W4ATL described, there's zero mechanical relay noise after the mod; it's as quiet ...

My new fav power supply is the Samlex line. They are the only one I've found so far that do NOT ground the 12V common line to the chassis. See my QRZ page for my campaign to get manufacturers to quit doing the common ground and similar USB shield grounding problems. Mike, Unknowingly, you likely ha...

...You just have to know the secret squirrel stuff, which is to type into the port setting box IP:port, e.g. "127.0.0.1:1800", or whatever you've got Thetis set to. So right where it says "COM10" or the like, just type right over the top of it. Thats works great. I didn't realiz...

Isn't this all a lot of effort when you can just switch to QSK and be done with it? That's what we're talking about. Inhibiting RL17 & RL19 while in CW (to minimize relay noise during QSK). 73 And, replacing the T/R relay. Replacing the T/R relay with an RF reed relay allows dialing down key-up...

Yep. The only reason for the Nano microcontroller is to sense the input key dit and dah lines and hold off on the PS relays for 500 ms just to unnecessarily have them engage and disengage with every keyed element. I sensed the key line this way as there was no other way to tap a circuit point on th...

Not sure how that would work since RL17 and RL19 are controlled differently. Right, it wouldn't work i.e. not without reprogramming the SPI commands sent to the relevant shift registers. But after thinking about this for an hour, I now remember the terrible trouble Phil and Rick were having with th...

RL17 and RL19 are both driven by identical but separate 8-bit shift registers. Register U5 controls T/R relay K5 and RL19, and U5 must remain connected to K5 to perform the T/R function. That's even better then! Move RL19 over to the unused pin on U10 (which already controls RL17) and inhibit both ...

RL17 and RL19 are both driven by identical but separate 8-bit shift registers. Register U5 controls T/R relay K5 and RL19, and U5 must remain connected to K5 to perform the T/R function. The OC driver is a ULN2003AD Darlington device. Each output channel is rated for 500 mA of current** so it's easi...

Paul I do plan to make the changes per your info. I am portable in NM using an Elecraft K3 as the rig. Spoiled by its soundless keying. No idea why Apache labs didn't go the pin diode route. Not only noisy but, using the internal keyer, I found needed large delays to keeps from hot keying. Not at a...

Paul, do you have photos showing the new relay and the mod for RL19 and 36 for the 7000 DLE? I think it will be a good ideal to modify Thetis in order to activate an OC output in CW mode or something similar. Volker DL4ZBG Sorry for the very late reply... The only photos I have are shown on my QRZ ...

Follow-up... I ordered three different types of blue SMD LEDs, each with a different luminous intensity (mcd) spec. I tried 72, 100 and 120 mcd. True to specs, the light output does change relative to the mcd value. The 120 mcd LED produces a blue light intensity closest to the original. It's a Dial...

I'd rather see no changes than this level of extra complexity. Seriously? How is making it easier to do SPLIT by automatically turning on MULTIRX (something that is essentially always needed, even in your case of out of band - just use the volume controls as intended!) - make it more complex? One b...