I played around some with the BF1105, and have to conclude that in this particular application, it's just a dumpster fire. There is no question the unwanted AM detection was coming from the BF1105 because, while it takes a couple of seconds for the microcontroller to boot and program the Si5351 for LO output, AM detection of WTWW or WBCQ - both huge signals at my QTH when they are on the air - occurs immediately upon power being applied to the BF1105 if they are on the air. I tried providing an adjustable voltage to Gate 2 to vary ( turn down ) the gain, and this was of little benefit in practice. Any gain at all seemed to invite the unwanted detection, although at lower gain levels, WRMI sounded fine until QSB would set in, then the unwanted AM detection would just overwhelm the intended signal. Unusable. Which is regrettable, as it was quite a hot performer when the big signals were off the air. As above noted, in the morning just after local dawn, WWVH was plainly audible underneath WWV. My only previous experience with BF1105 was in the development of the general coverage broadcast receiver, where, in a very early variant, it was used as a 45 MHz IF amplifier following a 2 pole crystal filter for initial selectivity. It worked well in that application, exhibiting none of the ill effects it demonstrated here, although I did not use it in the final variant of the receiver. Win W5JAG

The workaround published by qrp-gaijin works for me as well. Good work! Win W5JAG

Below are the spectrum displays of the two types of VFO's used here - the Si5351 LO and the AD 9850 DDS based LO. The Si5351 is a square wave based device, so all the harmonics are normal, and expected. All of the scruff surrounding the harmonics is more problematic, as they are fairly high level in amplitude, and, worse, move around, disappear, get generated at new frequencies, etc., while the device is being tuned. With the DC receiver, this is really audible as the device is tuned, The device is much easier to tune with the DDS based LO. It also sounds less noisy to me with the DDS, although I do not have the capability to measure that. Once the receiver is set to frequency, the difference is not too apparent. I probably would not build another DC receiver using an Si5351 based LO unless i intended to park it on a fixed frequency. Win W5JAG Si5351 DDS

Good work - I'll give it a try as soon as I get a chance.

That looks to be a reasonable conclusion on the evidence thus far, but, contra to that is Larry's assertion in a post a few below this, is that the forum has unlimited storage space. And I have certainly been a copious user of it, maybe more than my fair share, but pictures are fun, as well as helpful. So maybe it is a bug or a glitch like the spam filter was genenrating. Larry may not even be aware of this - I have not messaged him about it. I may try to edit the thread title to be more specific and maybe get his attention. I have some updates to make to my active threads, but I am holding off for now while this gets sorted out. At least that gives me more time to get caught up on your regenerative superhet thread - I;m a week to ten days behind on that, Win W5JAG

The .pdf file I tried to add was < 100 kb. That's pretty small. I've just gone back and cleared my cache, looked for problems on my end. I'm baffled. just tried it again with a 59 kB .pdf file. Adding any attachment requires a do over as far as I can tell.

Apparently, I am still in some sort of bizarre twilight zone posting regime. I was able to post a short text message to one of my threads. But, as soon as I added a picture to my post, the publish button disabled, and no amount of waiting for the picture to upload brought it back to life. Even more odd, removing the picture did not re enable the publish button. I have to discard the post, and start over again with new text. The same problem exists in this thread - trying to add a picture is a total post killer. Win W5JAG edit: nor can I edit a post to add an image. However, I can edit a post to add text as demonstrated here. second edit: nor can i edit a post to add a simple .pdf file. It gives the same result as an image - the update button disables, the edit has to be discarded, and the process to edit started over.

I tried the new front end out last night, BF1105 RF amp and HP IAM 81008 active mixer, and, wow, it was a hot mess of unwanted AM detection. But, really sensitive - at dawn this morning, it was easily hearing both WWVH and WWV on 5000 KHz. All of the unwanted detection is surely in the BF1105 - dual gate MOSFET's are notorious for it. Back to the drawing board.

The publish button is disabled. It doesn't seem to matter if I'm trying to add images, or just text. I've tried different browsers and my phone. I'm locked out of my threads, except this one, lol.

I've built a couple of prototypes, all of which were unsatisfactory to me, so I've decided to start over. Again. Lack of overall gain was a motivating factor in abandoning the previous prototypes, so the next variant is starting out with an RF amplifier. The active device is an NXP BF1105R, a UHF low voltage, high gain, low noise figure device especially made for RF amplifier use. All of the biasing resistors are in the die, making it a low parts count device and convenient to use. It is unusual in that it is an enhancement mode device, not that it matters much as a practical matter. The circuit is essentially the data sheet figure 16, with single tuned circuits on each end. Vds is +6 vdc. The tuned circuits are a couple of Amidon T-37-6 toroids, about 35 turns more or less, and approximately 3.5 uH. The parallel capacitance is about 300 pf, 60 pF of which is in the trimmer. Coupling in and out is by 3 turn links. Edit: when peaked at 5000 KHz, gain is approximately 45 dB. In the picture channel 2 (green) is the amp input; channel 1 (yellow) is the amp output. This gain number looks really high compared to old school dual gate MOSFET's like 40673, but the data sheet says 38dB typical at 200 Mhz, and there is a step up in the input transformer, so the gain number for the middle of the 60 meter shortwave band looks plausible. I'm testing it with 0.001 volts. 0.01 volts shows clear overload artifacts. I can decrease the voltage on Gate 2 if I need to turn the gain down.

A new Raduino. Functionally, it's exactly the same as the old Raduino, just more visually acceptable to me. In this variant, I used right angle pins on both sides of the Si5351 board and Pro Mini board to mount them vertically. This cuts the footprint in half in the horizontal dimension, and also creates a very rigid structure. This arrangement would be well suited to rough duty portable or mobile service. I swapped the LM317 for a 7805, but that's not of much consequence - just cut the parts count down some.

Hi, Larry - I just made a post, and then edited it, without any issues. Definitely working better. Win W5JAG

TDA7052A undergoing the Golden Earring "Moontan" stress test. This chip is from a lot of 10 I bought from AliExpress priced at 10 / $1 USD. I would ordinarily expect these to be counterfeit or sub standard in some way to the genuine article, of which I have examples for comparison. This chip sounds to be functioning about like I would expect. It's running at 8 volts. I might give it a go at 12. The input attenuator seems to be working correctly. I don't hear any hiss or distortion. Tentatively, it looks usable. I'm trying to avoid using an LM386, but the really high gain of the '386 is useful for simple receivers. Win W5JAG

The 6F7 looks to be a triode pentode combination, i.e. two separate tubes in one bottle, so more like a two transistor device. I suspect that a pentagrid converter like a 6BE6 or 6BA7, where one of the grids can act as a plate, might also work . Some of the GE Compactron tubes introduced at the end of the tube era, had three triodes in one bottle. Win W5JAG

Larry, I tried to edit my post - I needed to change "KHz" to "MHz" and the edited post got thrown into moderation.

My hope is that a simple two or three meter piece of wire connected to the top end ( high impedance ) of the input transformer, will give sufficient signal for satisfactory reception here at my QTH in Arkansas. The WRMI 100 kw transmitters are in south Florida, but the 5050 Khz antenna is beamed to the Caribbean Sea / South America region, so the continental United States is directly off the back of the antenna, or in a side lobe, so it’s probably more like trying to receive a 10 or 20 kw AM transmitter. The 9455 KHz antenna beams across the USA, and gives much better reception for me, but it usually only runs the programming I like beginning around midnight. The active antenna I have in the back of my mind, would just be the usual high gain amplified short rod, the disadvantage of course is that it will amplify everything from DC to VHF and then feed it to a front end that does not have a lot of filtering to start with. Of the two types of antenna, active, or regenerated ferrite rod, it seems clear to me that the regenerated rod would be the best choice. In addition to the benefits you mention, just the additional extra selectivity of a sharply tuned circuit in the front end would be beneficial. But I have no idea how to go about constructing such a device, so that will be a new learning curve for me if I go there. I’ve never been enthusiastic about regeneration. I had a simple, three transistor, regenerative general coverage receiver when I first became a ham, but it just didn’t work very well, and, like my poor initial experience with direct conversion, I just had no further interest in the receiver type and moved on to something else. Since becoming interested in RF homebrew again, after a very long absence, and having joined the ( former ) Radioboard, I cannot help but notice that regeneration is far and away the preferred receiver architecture for hams and broadcast listeners making homebrew receivers, to the point that almost anything else is just a novelty that really doesn’t generate a lot of interest. And the builders are enthusiastic about the performance of their regens. I figure attempting such an antenna might be a good way to join the party.

That's the same screen I got. I had never seen it before.

I've just encountered the same problem. I tried to post a new receiver project yesterday afternoon in solid state radios. The web page responded that it needed approval and it just disappeared. Hasn't been heard from since. Win W5JAG

When I need some stability of a vertical mounted toroid, I just secure them to the mounting surface with a blob of (Elmer's) white glue. This is fairly secure, and they can be removed just by pulling them loose and picking the hardened glue off them. It's not very pretty at all, but works okay. I didn't notice any detuning effects, but that could be a concern, I guess, in some uses. Win W5JAG

Those 3d models vaguely remind me of cordwood construction. NASA used it in some of the Apollo stuff. https://hackaday.com/tag/cordwood-construction/