Fair Radio Sales Surplus Macom 16179/3001-4033-00 Dummy Load

I got one of Fair Radio Sales surplus FAA-DUMMY dummy loads. It came marked Macom 16179 and 3001-4033-00, which is essentially unfindable. Presumably those are internal or customer part numbers for the component in its original application. Anyways, what is it and what's inside?

Overview of the load with an additional N-to-BNC bulkhead adapter

The above adapter is also from Fair Radio Sales, the UG-606 N female jack to bulkhead BNC female jack, removed from FAA equipment. Quite possibly the same set of assemblies as the load! Just right for mating to my cables for typical load use.

Came with free mounting hardware not pictured in the product listing. Given the lack of paste residue, presumably not used for substantial thermal link to the original equipment.

The connector assembly connects easily with four screws and matching lock-washers.

The interesting view: inside the flange connector to the resistive element and its connection to the overall block. Nice stainless RF path set into the aluminum.

The matching flange has a teflon socket with a pin hiding up inside on the coax. Retention screws on the side.

The coax to the N male plug is HARBOUR INDUSTRIES MIL-C-17/60C M17/60-RG-142 27478. Connector to flange length of about 8 inches.

Not pictured, throwing the load on my nanoVNA shows that it's nice and flat to the capabilities of the unit through 900 MHz, eventually (see below). Corresponds well to being intended for VHF/UHF equipment. Definitely would be decent to see what the 4.4 GHz v2 edition would say about it. Ohms out decently to about 50 at DC, plus resistance from cables and adapters.

Addendum: lessons in RF testing. The easiest way to start testing this was a different N to BNC adapter to connect to the pigtail that lives on my nanoVNA and to BNC to banana for going to the DMM. Initial SWR trace was horrid and DC ohms was showing various kiloohms, definitely not 50. Turns out, the center contact pin of the BNC side was covered in corrosion products from the adapter being very well aged kinda-NOS, not in a bag. Some friction cleaning got the tarnished silver a bit more exposed and it started working again. Just took comparing against a known-good commercial N 50 ohm termination to establish where in the chain things were messed up.

 

Comments

Post a Comment

Popular posts from this blog

Hardware Filter Modifications for Quansheng UV-K5 Band Extensions?

The Quansheng UV-K5 ( product page archive ) handheld transceiver has been notable in cheap amateur radios of 2023 by using both a wideband FM chip BK4819 ( product page archive ). With support of 18-620 and 840-1200 MHz half-duplex with 6.25/12.5/20/25 kHz channel spacing, this puts the chip in the range of five ITU Region 2 amateur bands (10m, 6m, 2m, 1.25m, 70cm, 33 cm) and spitting distance from a sixth (23 cm). Presumably hitting 4m and the rare 8m would be within reason as well. The easily hackable firmware indicates at least nominal receive capability up to 1300 MHz, though!
Read more

A Multi-Pronged Approach to BK4819 HT Band Expansion

As previously discussed, the BK4819 simplex FM transceiver chip with specified coverage of 18-660 and 840 to 1300 MHz covers a lot of Region 2 amateur radio bands with generally accepted FM operation: 10 m, 6 m, 2 m, 1.25 m, 70 cm, 33 cm, and 23 cm. The most popular models of amateur-oriented HTs using the chip generally only cover the popular VHF/UHF split with 2m and 70cm (and wide enough filters to support nearby business/public safety bands). How this is implemented varies in cost, complexity, and potential for effective modification. Of course, it's not really a modification if it's an actual product, but more on that further in.
Read more

MEAN WELL HLG-320H Power Supply Actual Teardown and Failure Investigation

Image
Last left off in the preview "teardown" despairing over the potting was my failed MEAN WELL HLG-320H. Then came a great need for mindless stimulation after a day of work and I tried cracking the case again. After the successful prying came picking and cutting away at the potting material to see what's what. Here's what's inside! Image warning: there's a lot to get through this whole device. Click on the photo for the full Blogger resolution. There you go, just a bit more force and the top plate comes off.
Read more