diff --git a/simpegEM/FDEM/FDEM.py b/simpegEM/FDEM/FDEM.py
index af27bf09..afee51b1 100644
--- a/simpegEM/FDEM/FDEM.py
+++ b/simpegEM/FDEM/FDEM.py
@@ -97,22 +97,20 @@ class ProblemFDEM_e(Problem.BaseProblem):
            u = self.fields(m)
 
         Jv = self.dataPair(self.survey)
+        dsig_dm = self.model.transformDeriv(m)
 
         for i, freq in enumerate(self.survey.freqs):
             e = u[freq, 'e']
             A = self.getA(freq)
             solver = Solver(A, options=self.solveOpts)
 
-            for tx in self.survey.getTransmitters(freq):
-                dMe_dsig = self.mesh.getEdgeInnerProductDeriv(m, v=e)
-                dsig_dm = self.model.transformDeriv(m)
+            for txi, tx in enumerate(self.survey.getTransmitters(freq)):
+                dMe_dsig = self.mesh.getEdgeInnerProductDeriv(m, v=e[:,txi])
 
+                P = tx.projectFieldsDeriv(self.mesh, u)
                 b = 1j*omega(freq) * ( dMe_dsig * ( dsig_dm * v ) )
-                Ab = solver.solve(b)
-
-                P  = tx.projectFieldsDeriv(self.mesh, u)
-
-                Jv[tx] = -P*Ab
+                Ainvb = solver.solve(b)
+                Jv[tx] = -P*Ainvb
 
         return Utils.mkvc(Jv)
 
@@ -120,7 +118,28 @@ class ProblemFDEM_e(Problem.BaseProblem):
     def Jtvec(self, m, v, u=None):
         if u is None:
             u = self.fields(m)
-        raise NotImplementedError('Jtvec todo!')
+
+        # Ensure v is a data object.
+        if not isinstance(v, self.dataPair):
+            v = self.dataPair(self.survey, v)
+
+        Jtv = np.zeros(self.model.nP, dtype=complex)
+
+        dsig_dm = self.model.transformDeriv(m)
+
+        for i, freq in enumerate(self.survey.freqs):
+            e = u[freq, 'e']
+            AT = self.getA(freq).T
+            solver = Solver(AT, options=self.solveOpts)
+
+            for txi, tx in enumerate(self.survey.getTransmitters(freq)):
+                dMe_dsig = self.mesh.getEdgeInnerProductDeriv(m, v=e[:,txi])
+
+                P  = tx.projectFieldsDeriv(self.mesh, u)
+                w = solver.solve(P.T * v[tx])
+                Jtv += - 1j*omega(freq) * ( dsig_dm.T * ( dMe_dsig.T * w ) )
+
+        return Jtv
 
 
 
diff --git a/simpegEM/Tests/test_FDEM.py b/simpegEM/Tests/test_FDEM.py
index 836ef717..a864b66b 100644
--- a/simpegEM/Tests/test_FDEM.py
+++ b/simpegEM/Tests/test_FDEM.py
@@ -2,6 +2,8 @@ import unittest
 from SimPEG import *
 import simpegEM as EM
 
+TOL = 1e-10
+
 class FDEM_bDerivTests(unittest.TestCase):
 
     def setUp(self):
@@ -26,7 +28,12 @@ class FDEM_bDerivTests(unittest.TestCase):
         rxList = EM.FDEM.RxListFDEM(XYZ, 'Ex')
         Tx0 = EM.FDEM.TxFDEM(None, 'VMD', 3, rxList)
 
-        survey = EM.FDEM.SurveyFDEM([Tx0])
+        x = np.linspace(5,10,3)
+        XYZ = Utils.ndgrid(x,x,np.r_[0])
+        rxList = EM.FDEM.RxListFDEM(XYZ, 'Ey')
+        Tx1 = EM.FDEM.TxFDEM(None, 'VMD', 3, rxList)
+
+        survey = EM.FDEM.SurveyFDEM([Tx0, Tx1])
 
         prb = EM.FDEM.ProblemFDEM_e(model)
         prb.pair(survey)
@@ -37,7 +44,7 @@ class FDEM_bDerivTests(unittest.TestCase):
         j_sx[4,4,4] = 1
         j_s = np.r_[Utils.mkvc(j_sx),np.zeros(mesh.nEy+mesh.nEz)]
 
-        prb.j_s = j_s
+        prb.j_s = np.c_[j_s, j_s]
         f = prb.fields(sigma)
 
         self.sigma = sigma
@@ -51,13 +58,15 @@ class FDEM_bDerivTests(unittest.TestCase):
         passed = Tests.checkDerivative(fun, x0, num=3, plotIt=False)
         self.assertTrue(passed)
 
-    # def test_Jtvec(self):
-    #     v = self.survey.nD
-    #     x0 = self.sigma
-    #     def fun(x):
-    #         return self.survey.dpred(x), lambda x: self.prb.Jvec(x0, x)
-    #     passed = Tests.checkDerivative(fun, x0, num=3, plotIt=False)
-    #     self.assertTrue(passed)
+    def test_Jtvec_adjointTest(self):
+        v = np.random.rand(self.survey.nD)
+        w = np.random.rand(self.prb.model.nP)
+
+        m = self.sigma
+        u = self.prb.fields(m)
+        vJw = v.dot(self.prb.Jvec(m, w, u=u))
+        wJtv = w.dot(self.prb.Jtvec(m, v, u=u))
+        self.assertTrue(vJw - wJtv < TOL)
 
 
 if __name__ == '__main__':