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More inductance is just more inductance in this circuit. Shouldn't matter whether its one or two coils that add up to the needed inductance. Seems to me we use between 7/10 and 1 uH for that. An open-core coil you can squeeze or stretch to trim the optimum value works for us. Try 7 or 8 turns...

I would start at the emitter of TR11 and see that the 7.3435 crystal isn't weak. Should see around 1 Volt peak-to-peak RF at TR11 emitter. There are other possible culprits, but they are all downstream from the AM-only mixer TR12 where this signal feeds to. This crystal is in a socket. If you...

Two steps forward, one step back. After running for about a half hour, the blower developed a rattle sound. Didn't matter what caused it. I had bought blowers for this project and have them on hand. The new one is quieter. Came from Amazon. Copped out and skipped making a metal bracket to...

A trimpot is not so different from a volume control. Sooner or later the resistor surface gets contaminated and the control becomes "scratchy". You can hear it in a volume control, but an internal adjustment simply acts erratic or wrong. A drop of cleaner, and a few excursions of the wiper...

The topside is looking a lot more legit. The pi-network tank coil it came with did not appeal to me. I have lots of D&A plated copper tubing. Removing the bogus ham-band coverage and band selector improves reliability in a Phantom or Maverick. And EET'S ALIYEEEV! Got lazy and bypassed...

Not to rain on this parade, but the crinkle-texture paint on the Plus Three/SSK mike is just soft. Unless the mike spent its life in a carton there will be dings. The display you mention might well require making friends with someone who has a media blaster and does powder coating. A mike...

I have installed and modified dozens of the PLJ-6LED counters. Never could see the point of 8 digits. The doc file above shows the 8-digit display is a lot fancier than the 6-digit. Not quite as simple to set up. 73

Somebody (else) needs to put together a proper cross-reference between the "LA"-prefixed numbers found in a Uniden-made product and the numeral-only IDs used in a radio made by RCI. There are more than a few overlaps where the same part has a different number in each factory. Now that the radio...

'nuff said. 73

Any chance the counter's metal case is touching the radio's chassis metal? The fiber washer between the module and the mounting surface serves to keep the two grounds separate. So does the plastic mount screw. Connecting the two separate ground circuits can cause some noises. 73

Good chance that 99% isopropyl alcohol will soften it enough to break it loose from the component and board surfaces. Won't attack any nearby thermoplastic material. 73

A sign the glue that holds the element to the housing is coming loose. 73

The display's offsets are hard-programmed into the counter chip in that radio. But the carrier oscillator frequency has to match. 10.695 for AM, 10.6975 for LSB and 10.6925 for USB. If those are off, the radio's output frequency won't match the counter. 73

Where the rubber meets the road is pin 4 of the TA7310. It has the 10.695 crystal feeding into it, and the 16 MHz VCO input to pin 4. We know the 10.695 works. If you have at least 4/10 of a Volt peak-to-peak at pin 4, the problem is downstream from there. Somewhere. Any chance the slug-tuned...

I understand the rules and wish to be entered into the drawing. 73

Haven't tried that. Only test them inside the mike's head. To test one in the "lollipop" round head we use a 1960s gadget meant for calibrating sound-level meters. Got it on fleabay decades ago. The straight output from the cartridge goes to the oscilloscope. Comparing the test head to our...

The air conditioner coil cleaner we've used for decades is mostly phosphoric acid, water and blue dye. Does a number on aluminum, brass and copper. Beware using it on anything silver plated. It will scrub the silver right off the surface. Called Lundmark Coil Cleen. There are others, but that's...

Have you tried powering the radio by its DC jack and an external power supply? A 1978 radio should have at least one oddball fault from electrolytic capacitors reaching their use-by date. At least this doesn't require a soldering iron to try. 73

So just what's on the other end of the blue/white wire? 73

Alignment is the first trobleshooting step for low transmit power. And if the only problem is a coil someone randomly "adjusted" way off of its peak setting, you fixed it with that alone. And if alignment alone doesn't cure a low-power issue, the behavior of those slug-tuned coils becomes a...