EMRFD Message Archive 13353

Message Date From Subject
13353 2016-12-14 08:19:42 Ravi Miranda PIN Diodes
Hi
I'm trying to locate a suitable (low cost) PIN diode for use in a VHF chain to act as a T/R switch as shown here: http://faculty.frostburg.edu/phys/latta/ee/qsk5/pindiodes/pindiodes.html

Criteria 144-148Mhz
Cost: Low
Type: Through hole
Location: UK

Suggestions welcome!

Thank you for your time.

Ravi/M0RVI

--
I'm here to add more value to the world than I'm using up.
13354 2016-12-14 08:39:49 Sandeep Lohia Re: PIN Diodes

Got some in my junk...
Don't ask number it's from MIL-Grade 25 Watt WEBEL SXA WTI,
& my eyes gone weak :)

Same old address in UK?
Alternative U can also use relays...

'Repair & Reuse or Recycle E-Waste'


13355 2016-12-14 09:08:05 cwfingertalker Re: PIN Diodes
Ravi,

I looked in the Digikey.com catalog and found two.  They are expensive.  About 17 dollars US each.  They have the MA4P4001B-402 and the MA4P4002B-402.  


73

Bill N7EU

 
13356 2016-12-14 09:28:34 Graham / KE9H Re: PIN Diodes
I suggest you Google the topic: 1N4007 as PIN diode.

Although not sold or represented as a PIN diode, it has a PIN like structure as a side effect of the high Voltage design.
The lower Voltage diodes in this family do not have the structure.
Using parts like this "off label" is controversial, but common at HF, where PIN diodes are even more rare and expensive.

--- Graham / KE9H

==

13357 2016-12-14 09:59:22 Claudio Girardi Re: PIN Diodes
The OP wrote it was for the 2 m band, the 1N4007 may not have good performances there.
Recently I did some measurements on (pseudo-)PIN diodes, including the 1N4007 but my focus was the HF band. I measured the low-level characteristics up to 300 MHz but did not test the large-signal performances beyond 30 MHz, see
http://www.qsl.net/in3otd/electronics/PIN_diodes/PIN_diodes.html
For narrowband VHF applications, the isolation could be improved by tuning out the diode capacitance but I did not try this.

73 de IN3OTD, Claudio

----Messaggio originale----
Da: "'Graham / KE9H' ke9h.graham@gmail.com [emrfd]"
Data: 14-dic-2016 5.28 PM
A:
Ogg: Re: [emrfd] Re: PIN Diodes

 

I suggest you Google the topic: 1N4007 as PIN diode.

Although not sold or represented as a PIN diode, it has a PIN like structure as a side effect of the high Voltage design.
The lower Voltage diodes in this family do not have the structure.
Using parts like this "off label" is controversial, but common at HF, where PIN diodes are even more rare and expensive.

--- Graham / KE9H

==

13358 2016-12-14 10:09:37 Dana Myers Re: PIN Diodes
13359 2016-12-14 20:35:45 mvs_sarma@ymail.c... Re: PIN Diodes
please try this link
 BA482 VHF PIN Diode

  regards

 sarma

 vu3zmv

13360 2016-12-15 03:57:18 Ravi Miranda Re: PIN Diodes
Hi
Thanks to everyone for responding, but there seems to be a limited number of options in the UK. RS does not stock these.

However, I found this: http://www.analog.com/media/en/technical-documentation/data-sheets/hmc574A.pdf

There are several solutions that are available in the IC space

Would this work? General idea seems ok. Max I will put 1-2W @2m on this.

Thank you

Ravi/M0RVI



13361 2016-12-15 06:18:57 Sandeep Lohia Re: PIN Diodes

Ravi ji,

I was unable to locate pin-diodes used in 25 Watt VHF in my own junk, will search again by week-end, this saturday...

However I found 5 Watt rockbound VHF handy once used by traffic police, & got 2 nos 'BA482' from there...

Also found 3 nos PCB of cheap long range wireless telephone PSTN ( on HAM band ) & was amazed to see in4148 there...
Hope I read right with lens & extra light.
Not yet looked at datasheet, & it's voltage rating. Nor I remember.
Previously used them only to switch Xtals.
Perhaps, Claudio can run a test...


'Repair & Reuse or Recycle E-Waste'


13362 2016-12-15 09:31:20 mvs_sarma@ymail.c... Re: PIN Diodes
please see this
 RS Stock No. 815-1184
 this appears apt for your needs RAVI jee
13372 2016-12-17 23:30:03 Bill Carver Re: PIN Diodes
GREAT data!
W7AAZ