Best MiniPCIe Wireless Cards for Custom AP

@jeff I've been having a heck of time finding quality right angle MMCX to Type-N Female Bulkhead assemblies which is whats needed for my enclosures. However, I did find the following company that allows for custom builds. Curious if you could tell me out of all their cabling options what would be best for 2.4, 5G and LTE? https://rfsupplier.com/customcable.html

I'm considering this configuration: Cable Type: 1.37; Length: 15.24cm/6inch(s); Connector 1: MMCX Right Angle Plug; Connector 2: N Straight Bulkhead Jack to be used with https://mikrotik.com/product/R11e-2HPnD

I've bought cases and commodity-grade antennas through their eBay storefront.

While they might make just great cables, it's hard to say anything about the quality of their offerings.

Type N connectors are overkill for a couple watts on the back of an enclosure. As you've found out, u.FL, MMCX, and the like take cables in the millimeter-diameter range, N connectors are generally used for cables in the centimeter or two range.

Have you considered a blanking panel and, for example, an SMA bulkhead connector?

Have you confirmed that it is MMCX that you need and not u.FL/IPEX?

https://www.nexsuninc.com/2017/11/03/comparing-small-form-factor-coaxial-rf-connectors/

Neither uFL/IPEX nor MMCX to N cables came up in Mouser's parametric search. Digikey has some that show up in their parametric search. You can find the Laird CA178 series at Mouser by name. I haven't used these, but at least they spec insertion loss and claim testing of the assembles.

Look at the specs on your cable and assembly for 2.4 GHz and 5 GHz insertion loss -- lower is better. Typically there is higher loss at higher frequencies. "LTE" could be anywhere from around 700 MHz into the 3-4 GHz range. If it's got good performance at 5 GHz, you're almost certainly going to be fine at 700 MHz.

Thanks so much for the information Jeff. I've considered the SMA bulkhead, however the issue is the most affordable generic enclosures that I've been able to find that fit the RBM33G board are Type-N so I'm not quite sure how it would work.

Regarding MMCX and UFL, I'm needing both at the LTE cards are UFL and Wifi cards MMCX.

I've discovered the best fit Laird cabling is LMR 100 noted here. However, the shortest I've been able to find is 12", and as you've stated the shorter the better - I only need 4"-6", so I'm thinking the custom build may be best.

The ones on the way for testing are RG316 noted here.

I'll be curious to hear your impressions of their build quality when you get the cables.

RG316 is not "fantastic" cable, often only rated up to 3 GHz or another datasheet. For a few inches, it should be OK -- you're likely to have more losses due to the connectors and their assembly. I'd definitely stay away from RG-174 as "normal" RG-174 is typically used at below 1 GHz and its losses at 5 GHz are significant (probably over 1 dB per foot)

In that size (~0.1" / 2.5 mm OD), the LMR-100 is a little bit better (dB per 100')

  • RG-316 -- (0.787) * sqrt(FMHz) + (0.0012) * FMHz
  • LMR-100 -- (0.709140) • sqrt(FMHz) + (0.001740) • FMHz

At 5 GHz:

  • RG-318 ~ 0.62 dB per foot
  • LMR-100 ~ 0.59 dB per foot

So for a foot or 30 cm or less, the difference is negligible.

Just found this online loss calculator -- http://kv5r.com/ham-radio/coax-loss-calculator/ -- which has several popular cables shown.


Edit:

Funny to see the Jameco link there -- They've been a mainstay here in the Bay Area for years and years but I never think of them as mail order (good peeps there). Sadly, HSC is officially closing, the last of the long-time component/surplus suppliers here.

It is with sincere regret that we announce the final days of HSC in Silicon Valley. After 54 years we will be closing our doors for the final time on Saturday, January 12, 2019.

Get external router.... a usb3 gigabit dongo....

Comparable price.... heat benefits.... adaptability / availability.......

Simpler.... Still though..... Very pertinant question OP........

@neheb I've created a script to monitor driver crashes if you'd like to use it: https://github.com/socomsystems/openwrt-radios-monitor How has your testing been coming along? I've recently experienced crashes using ath9k.

I haven't seen any recently.

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Is there a MiniPCIe card that can simultaneously function as independent AP's in the 2.4 and 5ghz bands?

No.

--
strictly speaking this is a lie, there is a single mt7615 card from AsiaRF offering that feature, but it's oversized, on the edge of cooling and power requirements, basically not available - and not supported by OpenWrt yet.

thanks for the reply.
I'm looking for a x86 solution that has dual band and a bunch of lan ports to replace my R7800 as it turned out to be the worst purchase I've done in quite a while! :frowning:

Many who use an x86 or other stand-alone router use either purpose-built "access points" or configure all-in-one routers as access points. This tends to be both the most cost-effective, as well as best-performing approach. By the time you get done with quality pigtails and antennas, any cost advantage is typically gone. [m]PCIe cards are generally built for client use, with any "ad-hoc" abilities secondary in their design.

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The r7800 might not meet your requirements in terms of routing performances beyond ~400 MBit/s, but the WLAN side of is top notch. You'd be hard pressed to find anything better than this (QCA9984) as an AP at this moment.

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can't I get a minipcie card with this chipset?

Regarding x86 and dual wifi, I will have to find a way. Having a separate AP is not an option as I don't like the clutter. Maybe a high power 5ghz mini pcie card and a high power usb 2.4ghz pen?

You can (e.g. from compex), but they are rather on the expensive side and not that commonly targetted at consumers (size, heat, power, prices).

This kind of question comes up frequently, but the basic answer is no. Feel free to search the forum here on both mPCIe and USB as access points.

"High power" and mPCIe slots generally don't get along well, especially with smaller mobos being unable to supply sufficient power. Consumer mobos also often don't have the clearance to accept anything more than a standard-sized card.

this particular board has two mini pcie slots, but one is tagged as being for ssd use. Can I put a mini pcie wlan card there? this way I could use one mini pcie slot for the 5hgz band and the other for 2.4ghz.

Would install openwrt on a pen drive and boot from there.

Please take the time to read the recommendations for reputable x86 boards and strongly against import crap at prices that are too good to be true, here, on the pfSense boards, and elsewhere. Realize that mPCIe slots aren't all the same in terms of connectivity, power supply, and card support. Reputable manufacturers will call this out in advance. Aliexpress and that ilk? Good luck.

Have you priced quality pigtails and antennas yet? Figure on spending US$20-50 per channel for them. Note that if you've got a 3x3 2.4 GHz and 3x3 5 GHz setup, that means six sets.

You've already been told that you aren't going to have satisfactory results with mPCIe or USB wireless cards/dongles in an AP situation.

I'm running 15 import mini pc craps since 2014 on my office without any problems. It's just that there is crap, and then, there is crap.

Regarding quality pigtails and antennas. What makes a pigtail and antenna a quality one, and what effect does it have to run a quality pigtail+antenna combo versus a non quality one? or is this like buying gold plated hdmi cables?

I'll try to sort it out with the manufacturer (s) if both slots can accept wlan cards.

No, real measurable differences, that can easily be 1-3 dB (half your power), and a lot more with non-professional quality components. With products not intended for the professional market, you could easily be losing 3/4 of your power (6 dB) or more.

"Yes, of course you can plug in any mPCIe card you'd like. If you have any problems, you can return it to us [at your expense] within 14 days of placing your order [and it takes 30 to arrive]."