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Re: Drake 2880 Converter



Hello this is Yoshi.

At 2001/01/29 06:48:53 Jesse Morris wrote:
> With a new round of Drake converters apparently on the way I thought
> there might be some in the group that would be interested in the fact
> that I blew the front end GASFET in another converter while testing
> antennas this afternoon.  It apparently happened while swapping the input
> cable from one antenna to another exactly like the last time.

  My first two 2880 became same, maybe the front FET had destroyed
with static voltage during I replcaing my antennas from temporaly
antenna base.
  I tried to repair these by replacing its FET with some HEMT GaAs
FET that I got from some parts shop. One is FHX35LG (about $3.00)
and the other is FHX14LP ($3.00), just replacing FET. After that
I tried to use them compairing with one more 2880 (original FET)
and the FHX35LG's one is working well as same as the original one.
So if you fried just only the FET, lets try to replace it with
FHX35LG. Maybe it will works good.

  And then, I connect a 30mm wire between the center pin of RF input
N connector and GND at inside of 2880's RF-IF shield case. It will
work as a quarter wavelength SHUNT BPF for 2.4GHz. This is the advice
from JA1JRZ Mr.Tusrumi on JAMSAT-bb.
  I did this for all of my three 2880s but the sensivity did not
down. This SHUNT wire will clip down the static voltage of RF-in so
I hope that my 2880s will not be destroyed by that.

  All 2880 of Millicom was bought up now so our japanese hams can
not get 2880 any more, so we should not put our 2880 in dustbox
even if it had broke. Lets try to fix it at first! FHX35LG is
cheap (JPY 350) and easy to get in Japan. I hope that it will
be same at US/EU.

  This morning, I tried to hear S2-MB of AO-40 with 29ele LOOP
and repaird 2880. I can get it during MA 4-37. Most of Blocks had
CRC errors but it was clear to hear. 2880 is working enough.

73 de Yoshi JF6BCC/KH2GR.

Yoshihiro Imaishi JF6BCC/KH2GR
mailto:jf6bcc@jarl.com
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