SMA adapter

[Matt285]

Looking for the best choice to adapt an SMA female to a male 3.5mm jack. Basically so that I can hook up the MLA-30 to a portable radio such as the Tecsun 660. I have seen some videos using up to three adapters, but I would like to use as few connections as possible. Your thoughts? Thanks

[ThaDood]

You might have to roll your own on that one. Here's where you can get the SMA female,   https://www.allelectronics.com/item/sma-2/sma-jack-amphenol/1.html
And, here's for the 3.5mm plug,   https://www.allelectronics.com/item/pmp-35/3.5mm-mini-phone-plug-special/1.html

Anyway, that's what I would do, and I've had to roll my own before, but not that combo. Good luck!!!!!

[Matt285]

Come to think of it I already have a couple of 3.5mm jacks. Thanks

[JimIO]

"You might have to roll your own on that one. Here's where you can get the SMA female,   https://www.allelectronics.com/item/sma-2/sma-jack-amphenol/1.html"

$1.25 Each for a SMA male PCB connector?!?! I think I got a bag of 20 for about that much. The 3.5mm is an oddball in the RF adapter department. You can get a SMA male to SMA male cable for $2-3. Cut in 2 and put a 3.5mm connector on each.

~

[JimIO]

 
   https://www.ebay.com/itm/SMA-Male-To-SMA-male-plug-connector-lot-Jumper-Coaxial-RG316-extension-cable/202144321942?_trkparms=ispr%3D1&hash=item2f10bd9196%3Am%3AmX22wlSMFZiuzIrRfRgEBpA&enc=AQAEAAACUBPxNw%2BVj6nta7CKEs3N0qXaPYafwFlB2BpGEEK4GwUdRY1a4Pz4gZbQjmz%2FmLLmKjohjQ3R%2F3SgAqXuf4TZKbVFaW%2BlSHoMFLokzZO42%2B7WW252nlOSGN0m45mR0bmp15BO4n0argtaylfN1u6XBVyocLFZvX3%2B%2Fysu8g4T924ID2KP7hVMCvZKcT%2Fi8LOpc5%2BoPn4EyybkcgC%2BiQCdq9HVM7Jk0d81ASJWMn%2B5PdOl%2FGoKjyg534Msvq%2Fc9b%2FIEUMBWSiTAJdkmP7STD%2BSRtPDi%2FML2sZTI2vNGEoMs11DutZVXclZR3woylpDdNERkr9x74xZRtTIWZA340tzZFZ5e2iF%2BLqZb%2BKWY%2F8uzx235QF0xMvU3g2Mru5xCT8kEbWd2uWX32x5smMUOCZfeOHvcA1N4B2i%2FQFrAw1BBHD4%2FyUISZvtPCauVpNqzYZbgXHxVZlwUJ243qSYQZyQOsq2G%2BWagFEkqGhfliYtNYUcFSKIeWtJEOJwcHMIKPGGR42unNMeovLmF8AwrD3cVVxDei9uUysvjex9wLMKipc4unbLBfI7S65qETV%2B%2FiDlRY9hMIS7wbCHClwNLrrBscAcpYEqYQ0ILx4DIcO3FrckrtNVy4zsjX9MsAqE%2B8zs562nOOZ8As1VRIYW79JxO7iMBa%2FX7fqm46dEi0tKFg9SuunoNRekFqqDVbbzerjRRhTwUOVEzZ7QJXIirXxHcmHvjMijF27kJo%2B6qsE5ga6qHChi4vYpj2xfXyzznQqc%2Bj%2FDaUBT0B8R4D2czvOdrpY%3D&checksum=202144321942958ec10c94114cbc9f9eba93da1fc6f8&enc=AQAEAAACUBPxNw%2BVj6nta7CKEs3N0qXaPYafwFlB2BpGEEK4GwUdRY1a4Pz4gZbQjmz%2FmLLmKjohjQ3R%2F3SgAqXuf4TZKbVFaW%2BlSHoMFLokzZO42%2B7WW252nlOSGN0m45mR0bmp15BO4n0argtaylfN1u6XBVyocLFZvX3%2B%2Fysu8g4T924ID2KP7hVMCvZKcT%2Fi8LOpc5%2BoPn4EyybkcgC%2BiQCdq9HVM7Jk0d81ASJWMn%2B5PdOl%2FGoKjyg534Msvq%2Fc9b%2FIEUMBWSiTAJdkmP7STD%2BSRtPDi%2FML2sZTI2vNGEoMs11DutZVXclZR3woylpDdNERkr9x74xZRtTIWZA340tzZFZ5e2iF%2BLqZb%2BKWY%2F8uzx235QF0xMvU3g2Mru5xCT8kEbWd2uWX32x5smMUOCZfeOHvcA1N4B2i%2FQFrAw1BBHD4%2FyUISZvtPCauVpNqzYZbgXHxVZlwUJ243qSYQZyQOsq2G%2BWagFEkqGhfliYtNYUcFSKIeWtJEOJwcHMIKPGGR42unNMeovLmF8AwrD3cVVxDei9uUysvjex9wLMKipc4unbLBfI7S65qETV%2B%2FiDlRY9hMIS7wbCHClwNLrrBscAcpYEqYQ0ILx4DIcO3FrckrtNVy4zsjX9MsAqE%2B8zs562nOOZ8As1VRIYW79JxO7iMBa%2FX7fqm46dEi0tKFg9SuunoNRekFqqDVbbzerjRRhTwUOVEzZ7QJXIirXxHcmHvjMijF27kJo%2B6qsE5ga6qHChi4vYpj2xfXyzznQqc%2Bj%2FDaUBT0B8R4D2czvOdrpY%3D&checksum=202144321942958ec10c94114cbc9f9eba93da1fc6f8&LH_BIN=1

[Josh]

A bit off topic but I assume a mla will crush the front end of a portable.

[Matt285]

That is an interesting point to bring up Josh. I have seen several videos posted that use the MLA-30 with standing portable receivers. I have never owned an antenna like this, so I'm not quite sure?

[JimIO]

The MLA30 Biasing Tee Outline.pdf schematic shows a potentiometer between the antenna and receiver connectors. USPS says mine should be here tomorrow.

~

[Josh]

That is an interesting point to bring up Josh. I have seen several videos posted that use the MLA-30 with standing portable receivers. I have never owned an antenna like this, so I'm not quite sure?

If it worked ok in the vids things should be ok for you too. That being said, if you're near an ambc sta, look out.

[chanito]

$8 https://ebay.us/81mghV



$10 https://www.amazon.com/dp/B076CVW6LC/ref=cm_sw_r_tw_dp_U_x_tHu5DbG7Q7CBE works well
SMA attenuators go for about $12 if you need to pad the MLA-30 down a bit.

[Matt285]

Excellent. Thank you Chanito. That's exactly what I need.

[Josh]

A connector with a short coax lead will reduce risk of stressing connectors over the typical solid metal adapter.

[KaySeeks]

Looking for the best choice to adapt an SMA female to a male 3.5mm jack. Basically so that I can hook up the MLA-30 to a portable radio such as the Tecsun 660. I have seen some videos using up to three adapters, but I would like to use as few connections as possible. Your thoughts? Thanks

"Regular" SMA connectors are mechanically compatible with 3.5 mm connectors. For that matter, they are mechanically compatible with 2.92 mm connectors as well. The only thing that you have to beware of is plugging a SMA male into a 3.5 mm or  2.92 mm female, where the "girth" (...ahem...) of the male plug may splay out the receptacle of the female (...ahem...). This does not appear to be what you are doing though so go for it.

If you don't believe me:

http://www.rfcafe.com/references/articles/Joe-Cahak/rf-connectors-cables-joe-cahak-6-2014.htm
(Scroll down to "Connector Adaptability".)

Some of the most used microwave connectors can adapt to different connectors. There are electrical and mechanical issues to those interfaces, but they can be done in a pinch. SMA, APC3.5 mm and 2.92 mm or K connectors can all be adapted to each other. 2.4 mm and 1.85 mm are also adaptable. The issues are the tolerance on the dimension and alignment of the pins. The lower quality SMA can damage the 3.5mm or 2.92mm connectors and should be gauged prior to using them. SMA center pin and socket has a gauge dimension tolerance of +/-0.01 and APC3.5 mm has +/-0.003. SMA connectors that are out of tolerance can damage the 3.5 mm precision connector or 2.92 mm that SMA can both adapt to.