====== HTOOL HT004A LNA Modifications ======

<blockquote>HT004A:\\
+30dB of RF Gain at 1000MHz-3300MHz\\
Bandwidth: 100K-6GHz\\
Max Output Power: + 20dBm (100mW) @ 1dB compression point</blockquote>

Purchasing:
  * [[https://item.taobao.com/item.htm?id=775926311040&skuId=5322051256398|HTOOL HT004A on Taobao]]
  * [[https://www.aliexpress.com/item/3256806583645456.html|HTOOL HT004A on AliExpress]]

===== Stock Components =====

  * **Input LNA (''Q1''):** Qorvo (Triquint) [[https://www.qorvo.com/products/p/TQP3M9008|TQP3M9008]] 50 - 4000 MHz High Linearity Low Noise Amplifier Gain Block
    * 50 - 4000 MHz
    * 20.6 dB gain, 1.3 dB NF
    * 5 V, 85 mA
  * **Output PA (''Q2''):** Qorvo (Sirenza) [[https://www.qorvo.com/products/p/SBB4089Z|SBB4089Z]] 50 - 6000 MHz Cascadable InGaP HBT Active Bias MMIC Amplifier
    * 50 - 6000 MHz
    * 15 dB gain, 4.5 dB NF
    * 5 V, 80 mA
  * **Battery charging IC (''U1'')**: [[http://toppwr.com/eproduct/view.php?id=478|TOPPOWER TP4056]]

===== Modifications =====

  * **Gain block upgrade**
    * Replace TQP3M9008 to [[https://www.qorvo.com/products/p/TQP3M9009|TQP3M9009]], Δ+1.2 dB gain, Δ+3.5 dB OIP3
    * Replace SBB4089Z to [[https://www.qorvo.com/products/p/SBB5089Z|SBB5089Z]], Δ-0.2 dB NF, higher OIP3 gain
    * Perhaps [[https://www.qorvo.com/products/p/SBB1089Z|SBB1089Z]] would be even better for satellite reception because of the narrower frequency range of 50 - 850 MHz
  * **Charging circuit delete** (no battery SKUs still ship with the charging circuit)\\ {{:projects:amateur_radio:modifications:img_6109.jpg?400|}}
    * Remove ''U1'' TP4056 (reduce noise)
    * Remove ''R3'', ''C6'', ''C11''
    * Remove ''D1'' and short with wire jumper (reduce noise and increase gain by removing supply voltage drop)